chore: v0.2.0 — 版本号收拢（6 处）

internal/version/version.go（ldflags 示例 + 默认值）、scripts/release.sh（注释 + 默认值）、 scripts/build_installers.sh、packaging/rpm/webui4frpc.spec（Version + changelog）、README.md 与 packaging/windows/README.md 的安装示例。按 v0.1.4 的 6 处清单逐个核对，无遗漏。rpm changelog 新增 0.2.0-1 条目，汇总本次「配置文件启动 + 口令脱敏」与「frpc user / transport 渲染修复」两组改动。
fix(render,store): frpc user 支持 + 修正 useEncryption/useCompression 渲染位置
2026-10-30 22:07:21 +00:00 · 2026-10-23 09:50:12 +08:00 · 2026-10-23 09:49:04 +08:00 · 2026-10-23 09:22:13 +08:00 · 2026-10-23 09:19:27 +08:00 · 2026-10-23 09:17:09 +08:00
34 changed files with 3575 additions and 350 deletions
--- a/.gitignore
+++ b/.gitignore
@ -22,6 +22,7 @@ data/

 # pi agent local state
 .pi/
+.pi-sessions/

 # docker demo staging (frp binaries)
 frp-bin/
--- a/README.md
+++ b/README.md
@ -32,6 +32,14 @@
  - 主负载信号：当前节点拥有的转发数（权重 ×100）
  - 次级信号：**NIC 网络接口利用率**（从 `/proc/net/dev` 增量 + `/sys/class/net/*/speed` 计算，排除了 lo/docker/veth 等虚拟接口）
  - 同转发数节点间由内存占用 + 网络饱和度打破平局
+- **负载均衡（自导式）**：每个节点对**自己的**转发跑同一条规则 —— 持有数超过
+  `ceil(总转发数 / 存活节点数)` 且至少 2 条时，自行撤销一条、把任务丢回环上，
+  再由环按「最闲者优先」重新认领
+  - **没有中心调度**：一节点的负载只有它自己的拓扑条目消失时才会下降，而条目是
+    本地簿记，没有对端能代它写，所以只能由持有者自己动手
+  - 规则自限：撤到平摊值即停（否则会把转发卸光），且低于下限永不撤、不会卸空节点
+  - 每节点默认 10 分钟冷却，限制抖动频率；默认 **dry-run**（只报告不释放）
+  - 集群页每节点一个开关：关闭 / 观察模式 / 启用，可持久化
 - **per-forward 独立进程**：每条转发拥有独立的 frpc 配置文件和 frpc 进程（worker 键 = `local~remote~port`），单条转发故障不影响兄弟，消除旧模型的多节点 `proxy already exists` 冲突
 - **容错自愈**：leader / 非 leader 节点宕机 → 自动检测 → 环跳过死亡节点、任务重挂；leader 宕机 → 上邻居晋升为新 leader
 - **宕机自动重联**：节点宕机重启后通过缓存的集群拓扑（对端地址 + 准入密钥）自动重联，显式脱离集群的节点不自动重联
@ -79,16 +87,16 @@ cd web && npm run build && rm -rf internal/httpapi/dist && cp -r web/dist intern
 ### Linux (Debian / Ubuntu)

 ```bash
-sudo dpkg -i webui4frpc-0.1.3-linux-amd64.deb   # 或 linux-arm64.deb
-sudo nano /etc/webui4frpc/webui4frpc.env        # 改掉默认密码
+sudo dpkg -i webui4frpc-0.2.0-linux-amd64.deb   # 或 linux-arm64.deb
+sudo nano /etc/webui4frpc/config.json           # 改掉默认密码（见「从配置文件启动」）
 sudo systemctl restart webui4frpc
 ```

 ### Linux (RHEL / Fedora / openEuler / 默认 / 龙蜥)

 ```bash
-sudo rpm -i webui4frpc-0.1.3-linux-x86_64.rpm
-sudo vi /etc/webui4frpc/webui4frpc.env
+sudo rpm -i webui4frpc-0.2.0-linux-x86_64.rpm
+sudo vi /etc/webui4frpc/config.json
 sudo systemctl enable --now webui4frpc
 ```

@ -97,7 +105,7 @@ sudo systemctl enable --now webui4frpc

 ### Windows

-双击 `webui4frpc-0.1.3-windows-amd64-setup.exe`（ARM 设备用 `windows-arm64-setup.exe`）。
+双击 `webui4frpc-0.2.0-windows-amd64-setup.exe`（ARM 设备用 `windows-arm64-setup.exe`）。
 安装向导会询问监听地址与管理员凭据，完成后：

 - 程序装到 `C:\Program Files\webui4frpc`
@ -107,8 +115,8 @@ sudo systemctl enable --now webui4frpc
 ### macOS

 ```bash
-sudo installer -pkg webui4frpc-0.1.3-darwin-arm64.pkg -target /   # Apple Silicon
-sudo installer -pkg webui4frpc-0.1.3-darwin-amd64.pkg -target /   # Intel
+sudo installer -pkg webui4frpc-0.2.0-darwin-arm64.pkg -target /   # Apple Silicon
+sudo installer -pkg webui4frpc-0.2.0-darwin-amd64.pkg -target /   # Intel
 ```

 或直接双击 `.pkg` 走图形安装器。安装后 launchd 开机自启，配置在
@ -126,7 +134,7 @@ sudo launchctl kickstart -k system/com.jianfeeeee.webui4frpc
 不想装服务只想跑一下，用对应的 `.tar.gz` / `.zip`，解压即用：

 ```bash
-tar xzf webui4frpc-0.1.3-linux-amd64.tar.gz
+tar xzf webui4frpc-0.2.0-linux-amd64.tar.gz
 ./webui4frpc -addr 127.0.0.1:7500 -user admin -password 你的密码 -workdir ./data
 ```

@ -144,12 +152,19 @@ sha256sum -c SHA256SUMS --ignore-missing
 ./webui4frpc -addr 127.0.0.1:7500 -user admin -password admin123 -workdir ./data
 ```

+或者用配置文件（推荐，口令不必出现在命令行与进程列表里）：
+
+```bash
+./webui4frpc -config ./config.json
+```
+
 打开 <http://127.0.0.1:7500/> ，输入账号密码进入画布。首次使用可到「设置」页一键安装 frpc（或手动指定路径），然后回到画布创建 local / remote 并连线、保存。

 ### 参数

 | 参数 | 默认 | 说明 |
 | --- | --- | --- |
+| `-config` | `<workdir>/config.json`（或 `$W4F_CONFIG`） | 配置文件路径；文件不存在不算错误 |
 | `-addr` | `127.0.0.1:7500` | 监听地址 |
 | `-user` / `-password` | `admin` / `admin` | Basic 认证（自动同步为 system 管理员账号） |
 | `-workdir` | `./webui-frpc` | 数据目录（db / 配置 / 日志 / bin） |
@ -160,6 +175,117 @@ sha256sum -c SHA256SUMS --ignore-missing

 环境变量 `W4F_HOST` 可覆盖节点对外可达的主机名（Docker DNS / 通配监听场景用）。

+## 从配置文件启动
+
+除了命令行 flag，也可以用 JSON 配置文件启动。**推荐用它承载口令**：命令行参数会出现在
+`ps` 输出、systemd 单元文件与 shell history 里，配置文件可以把口令放到只 root 可读的地方。
+
+### 优先级
+
+```
+命令行 flag  >  配置文件  >  内置默认值
+```
+
+- **只有显式传入的 flag 才会覆盖配置文件**。实现上用 `flag.Visit` 判断某个 flag 是否真的
+  被写在命令行上 —— Go 的 `flag` 包会先把默认值塞进变量，若直接读变量，默认值会无条件
+  压过配置文件。这是这套逻辑里唯一容易出错的地方，已有回归测试守着
+  （`internal/appconfig` 的 `TestResolveFileBeatsFlagDefaults`）。
+- 配置文件里**没写**或留空的字段，才回落到内置默认值。
+- `-peer` 特殊：显式传了 `-peer` 就用命令行的列表**整体替换**配置文件里的 `peers`，
+  而不是追加 —— 否则在命令行上删掉的对端会被配置文件复活。
+- `-join-key` 的内置默认是 `$W4F_JOIN_KEY`；未显式传 flag 时，配置文件里的 `join_key`
+  只在环境变量为空时才生效。
+- `-config` 未传时的查找顺序：`$W4F_CONFIG` → `<workdir>/config.json`。
+  注意 `workdir` 用的是 **flag 值**（显式或默认）：配置文件必须先能被找到，才谈得上
+  读取它里面的 `workdir`。
+- 文件**不存在不算错误**（回到旧的纯 flag 行为）；文件存在但 JSON 解析失败、出现未知键
+  （例如把 `password` 拼成 `passwd`）、或引用了未定义的环境变量，都会**立即报错退出**，
+  不会静默忽略 —— 静默回落到 `admin/admin` 才是真正的安全问题。
+
+### 字段
+
+字段与 flag 一一对应，全部可选：
+
+| 字段 | 对应 flag | 说明 |
+| --- | --- | --- |
+| `addr` | `-addr` | 监听地址 |
+| `user` | `-user` | Basic 认证用户名 |
+| `password` | `-password` | Basic 认证口令（推荐用 `${VAR}` 或 `file:`） |
+| `workdir` | `-workdir` | 数据目录 |
+| `bin` | `-bin` | 初始 frpc 二进制路径 |
+| `frpc` | `-frpc` | worker 默认 frpc 路径 |
+| `peers` | `-peer` | 集群对端 `host:port` 数组 |
+| `join_key` | `-join-key` | 集群准入密钥（也接受 `joinKey` 写法） |
+
+### 口令的两种写法
+
+所有字符串字段都支持这两种展开形式，不只是 `password`：
+
+```json
+{ "password": "${W4F_PASSWORD}" }
+```
+
+```json
+{ "password": "file:/etc/webui4frpc/secret/password" }
+```
+
+- `${VAR}` 取环境变量；变量**未定义或是空值**会报错退出（而不是展开成空口令）。
+  想写字面量 `$` 用 `$$`。
+- `file:/path` 只取文件的**第一行**（去掉行尾换行），适合 `chmod 600` 的 secrets 文件。
+  文件读不到会报错退出。
+- 展开后的值**不会**出现在任何日志里：启动横幅只打印「字段来源」与脱敏摘要
+  （`password=<redacted>`、`join-key=<redacted>`），`Values` 的 `String()` 也做了脱敏，
+  所以连手滑 `log.Printf("%v", ...)` 都不会漏。
+
+### 示例
+
+```json
+{
+  "addr": "0.0.0.0:7500",
+  "user": "jianf",
+  "password": "file:/etc/webui4frpc/secret/password",
+  "workdir": "/var/lib/webui4frpc",
+  "frpc": "/usr/local/bin/frpc",
+  "peers": ["10.0.0.2:7500", "10.0.0.3:7500"],
+  "join_key": "${W4F_JOIN_KEY}"
+}
+```
+
+对应的 systemd 单元不再需要把口令写进 `ExecStart`：
+
+```ini
+[Service]
+User=webui4frpc
+Group=webui4frpc
+EnvironmentFile=-/etc/webui4frpc/webui4frpc.env
+ExecStart=/usr/bin/webui4frpc -config /etc/webui4frpc/config.json
+ReadWritePaths=/var/lib/webui4frpc
+```
+
+`packaging/common/` 里带了一份可直接抄的单元模板与 `config.json` 示例。
+
+### 关于「没配口令」
+
+配置文件里没写 `password`、命令行也没给时，**行为与旧版一致**（回落到内置默认值），
+但启动日志会打一行明确警告：
+
+```
+WARNING: no password configured (neither -password nor the config file); using the built-in default — change it before exposing this node
+```
+
+### 负载均衡参数
+
+每节点独立生效；集群页的开关**优先于**这里的默认值（在页面上选过就以页面为准，重启不丢）。
+
+| 环境变量 | 默认 | 说明 |
+| --- | --- | --- |
+| `W4F_BALANCE_MODE` | `dry-run` | `off` 不参与 / `dry-run` 只报告 / `on` 真正释放 |
+| `W4F_BALANCE_COOLDOWN` | `600` | 同一节点两次释放之间的最小秒数 |
+| `W4F_BALANCE_INTERVAL` | `10` | 检查间隔（秒） |
+
+**释放会停掉该转发的 frpc worker，其上的在途连接会断一次**，由新节点认领后恢复；
+因此默认是 `dry-run`。集群页的开关走 write 级权限。
+
 ### 启动行为

 节点启动时的集群引导优先级：
@ -191,10 +317,10 @@ webui4frpc（单二进制，无 frp 依赖，前端 go:embed）
 │   ├── render               渲染 frpc JSON 配置（per-forward 单 proxy + 高级参数 + LB/健康检查）
 │   ├── process              worker 进程管理（spawn/stop/restart/自愈/日志轮转，worker 键 = local~remote~port）
 │   ├── install              一键下载官方 frpc（GitHub Releases，含解压安全防护）
-│   ├── cluster              令牌环协议（ring engine / leader 选举 / 容错 / 宕机重联 / 二进制分发 / NIC 负载采样）
+│   ├── cluster              令牌环协议（ring engine / leader 选举 / 容错 / 宕机重联 / 二进制分发 / NIC 负载采样 / 自导式负载均衡）
 │   └── httpapi              REST API + 静态资源（auth/session / canvas / forwards / cluster / users / audit 导出）
 └── web/                     Vue 3 SPA（Element Plus + VueFlow 画布 + Pinia）
-    └── src/views/           状态总览 / 连接配置（画布）/ 集群 / 设置 / 账号与密钥
+    └── src/views/           状态总览 / 连接配置（画布）/ 集群（含负载均衡开关）/ 设置 / 账号与密钥
 ```

 ## API
@ -220,6 +346,8 @@ webui4frpc（单二进制，无 frp 依赖，前端 go:embed）
 | | GET | `/binary/status` | read | frpc 路径 |
 | | POST | `/binary/install` | write | 安装 frpc |
 | **集群** | GET | `/cluster/ring` | read | 令牌环快照 |
+| | GET | `/cluster/balance` | read | 本节点负载均衡视图（只读，不变更状态） |
+| | POST | `/cluster/balance/mode` | write | 切换本节点负载均衡模式（持久化） |
 | | POST | `/cluster/create` | write | 创建独立集群 |
 | | POST | `/cluster/join-ring` | write | 加入集群（本节点发起） |
 | | POST | `/cluster/join` | write | 接收新节点加入 |
@ -254,8 +382,45 @@ webui4frpc（单二进制，无 frp 依赖，前端 go:embed）
 - **任务分发**：在任意节点画布上配置 `localOnly=false` 的转发并保存 → 画布差异判断生成命令 → 令牌携带 → 负载最低节点摘取 → 拉起 frpc worker
 - **容错**：节点宕机 → 自动检测 → 环自愈（跳过死亡节点 / leader failover）；重启 → 自动重联
 - **退出集群**：在集群页「退出集群」→ 本节点脱离为 standalone，不自动重联
+- **负载均衡**：见下节

-集群页展示：环拓扑（self/leader 标记）、令牌轮次、节点负载、待办任务、活跃转发拓扑（含 owner 归属）、增量事件日志。
+集群页展示：环拓扑（self/leader 标记）、令牌轮次、节点负载、待办任务、活跃转发拓扑（含 owner 归属）、负载均衡（本机份额与释放计划）、增量事件日志。
+
+### 负载均衡（自导式释放）
+
+**为什么不是 leader 统一调度**：一节点的负载信号是它持有的转发数，而这个数只在
+**它自己的拓扑条目消失**时才下降 —— 条目是本地簿记。所以 leader 从外面只能*看见*
+失衡，无法*消除*它；要消除就得伸手改另一个节点的簿记，而这正是这个环到处都在避免
+的跨节点写（撤销、重启同样都是定向往 owner）。
+
+于是规则由每个节点对自己的转发本地执行：
+
+```
+当  持有转发数 >= 2  且  持有转发数 > ceil(总转发数 / 存活节点数)
+则  撤销其中一条 → 删除条目 → 以启用状态重新发布到环 → 由最闲节点认领
+```
+
+- **自限**：撤到平摊值即停。3 条分 3 台时，持有 2 条的那台卸一条后变成 1 条，
+  `1 > 1` 不成立 → 停手。没有这个上界，owner 会把转发全部卸光。
+- **不会卸空**：低于下限 2 条永不撤销。
+- **不碰已停用的转发**：停用条目的 entry 是用户「停用」决定的载体，释放它等于把
+  一条**已停**的转发当活干交给别人。
+- **释放 ≠ 停止**：用户停止保留条目并标记链路为停用；均衡释放**删除条目**且链路保持
+  启用。两者不能混用 —— 复用停止的话，每个节点的重复认领守卫都会拒绝这条已是「有主」
+  的转发，它会被永久搁死在刚放弃它的那台机器上。
+
+三种模式（集群页每节点一个开关，也可用 `W4F_BALANCE_MODE` 设默认值）：
+
+| 模式 | 行为 |
+| --- | --- |
+| `off` | 不参与均衡 |
+| `dry-run` | 只报告「将释放哪条」，不动任何东西（默认） |
+| `on` | 真正释放 |
+
+只读接口 `GET /cluster/balance` 返回本节点视角：`selfForwards` / `share` /
+`totalForwards` / `aliveNodes` / `selfOverShare`、`wouldRelease`、`releasing`、
+`blockedBy`（为何暂不动的机器原因）、`mode` / `modeSource` / `canControl`。
+该接口**不改变任何状态** —— 反复轮询不会启动、延迟或取消一次释放。

 ## 测试

@ -263,6 +428,9 @@ webui4frpc（单二进制，无 frp 依赖，前端 go:embed）
 # 后端
 go test ./...

+# 单包（负载均衡规则与状态机）
+go test ./internal/cluster/ -run TestShare -v
+
 # 前端类型检查
-cd web && npm run type-check
+cd web && npm run build
 ```
--- a/cmd/webui4frpc/main.go
+++ b/cmd/webui4frpc/main.go
@ -15,10 +15,12 @@ import (
 	"os"
 	"os/signal"
 	"path/filepath"
+	"strconv"
 	"strings"
 	"syscall"
 	"time"

+	"webui4frpc/internal/appconfig"
 	"webui4frpc/internal/cluster"
 	"webui4frpc/internal/httpapi"
 	"webui4frpc/internal/install"
@ -29,18 +31,68 @@ import (
 )

 func main() {
-	addr := flag.String("addr", "127.0.0.1:7500", "listen address")
-	user := flag.String("user", "admin", "basic auth user")
-	pass := flag.String("password", "admin", "basic auth password")
-	workdir := flag.String("workdir", "./webui-frpc", "data directory (db, configs, logs, bin)")
-	bin := flag.String("bin", "", "initial frpc binary path (optional; defaults to manual/auto-install)")
-	frpc := flag.String("frpc", "", "default worker frpc binary path (fallback when settings has none)")
-	var peers multiFlag
-	flag.Var(&peers, "peer", "cluster peer host:port (repeatable; same creds)")
-	joinKey := flag.String("join-key", os.Getenv("W4F_JOIN_KEY"), "cluster join key = the sponsor node's nodeKey (required with -peer to join an existing cluster)")
+	addrF := flag.String("addr", "127.0.0.1:7500", "listen address")
+	userF := flag.String("user", "admin", "basic auth user")
+	passF := flag.String("password", "admin", "basic auth password")
+	workdirF := flag.String("workdir", "./webui-frpc", "data directory (db, configs, logs, bin)")
+	binF := flag.String("bin", "", "initial frpc binary path (optional; defaults to manual/auto-install)")
+	frpcF := flag.String("frpc", "", "default worker frpc binary path (fallback when settings has none)")
+	joinKeyF := flag.String("join-key", os.Getenv("W4F_JOIN_KEY"), "cluster join key = the sponsor node's nodeKey (required with -peer to join an existing cluster)")
+	var peersF multiFlag
+	flag.Var(&peersF, "peer", "cluster peer host:port (repeatable; same creds)")
+	configF := flag.String("config", "", "config file path (default <workdir>/config.json, or $W4F_CONFIG; a missing file is not an error)")
 	flag.Parse()

-	wd, err := filepath.Abs(*workdir)
+	// Merge config file with flags. Priority: explicit flag > config file >
+	// built-in default. The explicit set comes from flag.Visit because Go
+	// hands us each flag's default unconditionally — reading the pointer
+	// blindly would let a default silently clobber the file.
+	explicit := appconfig.ExplicitSet(flag.CommandLine)
+	cfgPath := *configF
+	if cfgPath == "" {
+		// W4F_CONFIG (packaged systemd units use it) outranks the default
+		// location, but never an explicit -config.
+		cfgPath = strings.TrimSpace(os.Getenv("W4F_CONFIG"))
+	}
+	if cfgPath == "" {
+		cfgPath = appconfig.DefaultPath(*workdirF)
+	}
+	cfgFile, err := appconfig.Load(cfgPath)
+	if err != nil {
+		// Present but unparsable/undeclared-key config fails loudly: silently
+		// falling back to built-in defaults would quietly boot admin/admin.
+		log.Fatalf("%v", err)
+	}
+	v, srcs := appconfig.Resolve(
+		appconfig.Defaults{Addr: "127.0.0.1:7500", User: "admin", Password: "admin", WorkDir: "./webui-frpc"},
+		appconfig.Values{
+			Addr: *addrF, User: *userF, Password: *passF, WorkDir: *workdirF,
+			Bin: *binF, FRPC: *frpcF, Peers: []string(peersF), JoinKey: *joinKeyF,
+		},
+		explicit, cfgFile,
+	)
+	// Redacted summary + per-field sources. Never the values themselves: the
+	// basic-auth password must not reach stdout, the journal, or a log file.
+	if cfgFile == nil {
+		log.Printf("config: no file at %s (flags only); %s", cfgPath, v.Summary())
+	} else {
+		log.Printf("config: loaded %s; %s", cfgPath, v.Summary())
+	}
+	log.Printf("config: precedence flag>file>default — addr<-%s user<-%s workdir<-%s", srcs.Addr, srcs.User, srcs.WorkDir)
+	switch srcs.Password {
+	case appconfig.SourceFile:
+		log.Printf("config: password <- file (value not logged)")
+	case appconfig.SourceDefault:
+		// Neither -password nor the config file provided one. Behaviour is
+		// unchanged (the legacy default still applies) but say so out loud:
+		// a node serving the UI with a well-known password deserves a warning.
+		log.Printf("WARNING: no password configured (neither -password nor the config file); using the built-in default — change it before exposing this node")
+	}
+	if v.Password == "" {
+		log.Printf("WARNING: password is empty — basic auth admin login will not work")
+	}
+
+	wd, err := filepath.Abs(v.WorkDir)
 	if err != nil {
 		log.Fatalf("resolve workdir: %v", err)
 	}
@ -61,14 +113,14 @@ func main() {
 	// account setup. The auth middleware's Basic branch still falls back to the
 	// raw flag creds, so inter-node cluster traffic (which uses SetBasicAuth
 	// with these flags) never breaks even before this row exists.
-	if err := st.SyncSystemUser(*user, *pass); err != nil {
+	if err := st.SyncSystemUser(v.User, v.Password); err != nil {
 		log.Fatalf("sync system user: %v", err)
 	}

 	// Seed settings with the initial binary path if provided.
-	if *bin != "" {
+	if v.Bin != "" {
 		cfg, _ := st.Settings()
-		cfg.BinaryPath = *bin
+		cfg.BinaryPath = v.Bin
 		_ = st.UpdateSettings(cfg)
 	}

@ -77,10 +129,10 @@ func main() {
 	// own webui binary as frpc. So fallback is empty unless -bin is set; the UI
 	// then asks the user to install or provide frpc.
 	fallbackBin := ""
-	if *frpc != "" {
-		fallbackBin = *frpc
-	} else if *bin != "" {
-		fallbackBin = *bin
+	if v.FRPC != "" {
+		fallbackBin = v.FRPC
+	} else if v.Bin != "" {
+		fallbackBin = v.Bin
 	}

 	pm := process.NewManager(process.Options{
@ -112,15 +164,15 @@ func main() {

 	reg := cluster.NewRegistry(filepath.Join(wd, "bin"))
 	// M6: register cluster peers from -peer flags (same creds as this node).
-	for _, p := range peers {
-		reg.RegisterPeer(p, p, *user, *pass)
+	for _, p := range v.Peers {
+		reg.RegisterPeer(p, p, v.User, v.Password)
 	}

 	// M6 token ring: this node is the initial leader of the cluster ring
 	// (creation node). Engine drives two-phase cycles; transport POSTs the
 	// token to the successor over HTTP.
-	selfID := reachableAddr(*addr)
-	ringTransport := &cluster.TokenTransport{User: *user, Pass: *pass}
+	selfID := reachableAddr(v.Addr)
+	ringTransport := &cluster.TokenTransport{User: v.User, Pass: v.Password}
 	// nodeKey is this node's cluster admission key. It is NOT generated at
 	// startup — a fresh node has no key until it creates or joins a cluster.
 	// A creation node (no -peer) generates its key on CreateCluster; a joiner
@ -133,7 +185,7 @@ func main() {
 	}
 	var ring *cluster.Engine
 	ring = cluster.NewEngine(
-		selfID, selfID, *user, *pass, version.Version, nil,
+		selfID, selfID, v.User, v.Password, version.Version, nil,
 		&cluster.AppHandler{
 			LoadFn: func() (float64, float64) {
 				// NetPct: real NIC saturation from /proc/net/dev deltas vs
@ -289,6 +341,21 @@ func main() {
 				log.Printf("ring[%s] revoked task %s: %s→%s:%d", selfID, tk.ID, tk.Local.Name, tk.Remote.Name, tk.Link.RemotePort)
 				return nil
 			},
+			// ReleaseFn stops this forward's worker for a REBALANCE, leaving the
+			// link ENABLED. This must not reuse RevokeFn: that marks the link
+			// stopped, and the released forward is about to run on another node —
+			// a "stopped" flag would make the claim path treat the re-published
+			// task as a disabled forward and refuse to start a worker for it,
+			// leaving the forward dead everywhere.
+			ReleaseFn: func(ctx context.Context, tk *cluster.Task) error {
+				key := process.WorkerKey(tk.Local.Name, tk.Remote.Name, tk.Link.RemotePort)
+				if _, running := pm.Status(key); running {
+					_ = pm.Stop(key)
+				}
+				log.Printf("ring[%s] released worker %s (rebalancing): %s→%s:%d", selfID, key,
+					tk.Local.Name, tk.Remote.Name, tk.Link.RemotePort)
+				return nil
+			},
 			// RestartFn brings an already-claimed forward back after a stop. It
 			// must NOT run the claim bookkeeping (ClaimFn), which appends links and
 			// writes topology state: the forward is already established, and a stop
@ -338,7 +405,7 @@ func main() {
 			}
 			return nodeID
 		}),
-		selfID, len(peers) == 0, nodeKey, // creation node (no -peer) is the initial leader
+		selfID, len(v.Peers) == 0, nodeKey, // creation node (no -peer) is the initial leader
 	)
 	// Install the persistence callbacks so ensureNodeKey (called from
 	// CreateCluster / AdoptState) and detachAsStandalone can persist/clear
@ -388,6 +455,11 @@ func main() {
 		}
 	})

+	// Load balancer is created here (before the Handler) so the HTTP layer can
+	// expose its read-only report. Mode/parameters are applied further down, once
+	// the W4F_BALANCE_* environment has been parsed.
+	balancer := cluster.NewBalancer(ring, 600)
+
 	h := &httpapi.Handler{
 		Store:    st,
 		Process:  pm,
@ -396,12 +468,15 @@ func main() {
 		Sessions: httpapi.NewSessionStore(),
 		Cluster:  reg,
 		Ring:     ring,
+		// Balancer is created above, before the environment that configures it is
+		// parsed, because the HTTP layer needs the pointer.
+		Balancer: balancer,
 		// SelfAddr must be reachable by peers. 0.0.0.0/empty on a real host
 		// would break peer reconnect, so fall back to the hostname (container
 		// name inside docker is a routable addr on the compose network).
-		SelfAddr: reachableAddr(*addr),
-		User:     *user,
-		Password: *pass,
+		SelfAddr: reachableAddr(v.Addr),
+		User:     v.User,
+		Password: v.Password,
 		BinaryPath: func() string {
 			s, _ := st.Settings()
 			if s.BinaryPath != "" {
@ -506,10 +581,10 @@ func main() {
 	if err != nil {
 		log.Fatalf("build handler: %v", err)
 	}
-	srv := &http.Server{Addr: *addr, Handler: handler}
+	srv := &http.Server{Addr: v.Addr, Handler: handler}

 	go func() {
-		log.Printf("webui-frpc listening on %s (workdir %s)", *addr, wd)
+		log.Printf("webui-frpc listening on %s (workdir %s)", v.Addr, wd)
 		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
 			log.Fatalf("server error: %v", err)
 		}
@ -542,8 +617,8 @@ func main() {
 	}
 	if persistedPeers != "" {
 		go retryRejoinCached(clusterCtx, ring, persistedPeers)
-	} else if len(peers) > 0 {
-		go retryJoinCluster(clusterCtx, ring, peers[0], *joinKey)
+	} else if len(v.Peers) > 0 {
+		go retryJoinCluster(clusterCtx, ring, v.Peers[0], v.JoinKey)
 	} else {
 		if err := ring.CreateCluster(); err != nil {
 			log.Printf("ring[%s] create cluster at startup: %v", selfID, err)
@ -553,6 +628,65 @@ func main() {
 	go ring.WatchTokenLoss(clusterCtx)
 	go ring.WatchLeader(clusterCtx)

+	// Load balancing — SELF-DIRECTED, and dry-run by default.
+	//
+	// Every node runs this check against its OWN forwards. There is no
+	// coordinator: a node's load only actually falls when its own topology entry
+	// goes away, so only the owner can produce the state change that makes the
+	// ring hand a forward to somebody else. The node gives a forward up and
+	// re-publishes it as an ordinary unclaimed task; the ring's normal
+	// lowest-load claim then places it. (The earlier design had the leader pick a
+	// victim and a destination — but it can only see the imbalance, not resolve
+	// it, so it had to reach into another node's bookkeeping to make its decision
+	// true.)
+	//
+	// A release stops a worker and drops a live connection, so acting on the ring
+	// is opt-in:
+	//
+	//   W4F_BALANCE_MODE=dry-run   report the decision, release nothing (default)
+	//   W4F_BALANCE_MODE=on        actually release
+	//   W4F_BALANCE_MODE=off       do nothing at all
+	//   W4F_BALANCE_COOLDOWN=600   min seconds between two releases by one node
+	//   W4F_BALANCE_INTERVAL=10    check every N seconds
+	balMode := strings.ToLower(strings.TrimSpace(os.Getenv("W4F_BALANCE_MODE")))
+	if balMode == "" {
+		balMode = cluster.BalanceDryRun
+	}
+	balInterval := time.Duration(envFloat("W4F_BALANCE_INTERVAL", 10)) * time.Second
+	if balInterval < time.Second {
+		balInterval = 10 * time.Second
+	}
+	balCooldown := int64(envFloat("W4F_BALANCE_COOLDOWN", 600))
+	balancer.SetCooldown(balCooldown)
+	balancer.SetMode(balMode)
+	// A mode stored from the cluster page wins over the environment, so flipping
+	// the switch is not silently reverted by the next restart. SetMode is applied
+	// first so a stored value only has to be a no-op when the two agree.
+	balancer.SetModePersistence(
+		func() (string, bool) {
+			m, ok, err := st.BalanceMode()
+			if err != nil {
+				log.Printf("ring[%s] read stored balance mode: %v", selfID, err)
+				return "", false
+			}
+			return m, ok
+		},
+		func(m string) error {
+			s, err := st.Settings()
+			if err != nil {
+				return err
+			}
+			s.BalanceMode = m
+			return st.UpdateSettings(s)
+		},
+	)
+	// Report the EFFECTIVE mode, not balMode: a stored value may have overridden
+	// the environment, and a startup line naming the wrong mode is exactly how an
+	// operator ends up believing releasing is off while it is on.
+	log.Printf("ring[%s] load balancing %s (source=%s cooldown=%ds interval=%s, self-directed)",
+		selfID, strings.ToUpper(balancer.Mode()), balancer.ModeSource(), balCooldown, balInterval)
+	go balancer.Watch(clusterCtx, balInterval)
+
 	// Startup reconcile: every node (leader or not) checks its own topology
 	// entries and re-claims any whose per-forward frpc worker process is
 	// absent — the topology was recovered via AdoptState but the worker
@ -735,6 +869,22 @@ func retryJoinCluster(ctx context.Context, ring *cluster.Engine, targetAddr, joi
 	}
 }

+// envFloat reads a numeric environment variable, returning def when unset or
+// unparseable. A malformed value must not silently change behaviour, so it falls
+// back to the documented default rather than 0.
+func envFloat(key string, def float64) float64 {
+	v := strings.TrimSpace(os.Getenv(key))
+	if v == "" {
+		return def
+	}
+	f, err := strconv.ParseFloat(v, 64)
+	if err != nil {
+		log.Printf("env %s=%q is not a number; using %v", key, v, def)
+		return def
+	}
+	return f
+}
+
 // retryRejoinCached is the crash/restart recovery path: parse the persisted
 // peer list (JSON of [{addr,key},...]) and try to rejoin via each peer in
 // order. The first peer that accepts wins. Retry the whole list every 10s
--- a/internal/appconfig/appconfig.go
+++ b/internal/appconfig/appconfig.go
@ -0,0 +1,197 @@
+// Package appconfig implements webui4frpc's startup config file support.
+//
+// Resolution order (documented in README):
+//
+//	command-line flag > config file > built-in default
+//
+// A flag only overrides the file when it was explicitly passed on the command
+// line (flag.Visit). Go's flag package would otherwise hand us a default value
+// and silently clobber whatever the file said — that is the single easiest way
+// to get this wrong, so Resolve never compares values against defaults.
+//
+// Two value expansion forms are supported in every string field:
+//
+//	${VAR}      -> environment variable (undefined => loud error)
+//	file:/path  -> first line of /path (trailing CR/LF trimmed)
+//
+// Expanded values are never logged; callers print field *sources* only
+// (see Summary).
+package appconfig
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// File is the on-disk schema of config.json. Every field is optional; the
+// pointers are not used here because callers treat "" / nil slice as "unset"
+// (a config file cannot express a meaningful empty addr or empty user).
+type File struct {
+	Addr     string   `json:"addr"`
+	User     string   `json:"user"`
+	Password string   `json:"password"`
+	WorkDir  string   `json:"workdir"`
+	Bin      string   `json:"bin"`
+	FRPC     string   `json:"frpc"`
+	Peers    []string `json:"peers"`
+	// join_key is the documented spelling; joinKey is accepted as an alias
+	// because the rest of the project uses camelCase in JSON payloads.
+	JoinKey      string `json:"join_key"`
+	JoinKeyCamel string `json:"joinKey"`
+}
+
+// UnmarshalJSON decodes the config object, ignoring keys that start with "_".
+//
+// Sample files ship with "_comment"/"_optional" documentation inside the JSON,
+// and comment keys must not be able to mask a real typo: everything else is
+// still decoded with DisallowUnknownFields (see decodeStrict).
+func (f *File) UnmarshalJSON(data []byte) error {
+	var raw map[string]json.RawMessage
+	if err := json.Unmarshal(data, &raw); err != nil {
+		return err
+	}
+	for k := range raw {
+		if strings.HasPrefix(k, "_") {
+			delete(raw, k)
+		}
+	}
+	clean, err := json.Marshal(raw)
+	if err != nil {
+		return err
+	}
+	type alias File // avoid recursing into this method
+	if err := decodeStrict(clean, (*alias)(f)); err != nil {
+		return err
+	}
+	// decodeStrict expects an object; re-validate that at least an object was
+	// given (a bare number/array would already have failed above).
+	return nil
+}
+
+// decodeStrict decodes exactly one JSON value, rejecting unknown fields and
+// trailing data.
+func decodeStrict(data []byte, v any) error {
+	dec := json.NewDecoder(bytes.NewReader(data))
+	// Reject unknown keys: a typo such as "passwd" would otherwise silently
+	// leave the password at its built-in default, which is a security bug
+	// disguised as a config typo.
+	dec.DisallowUnknownFields()
+	if err := dec.Decode(v); err != nil {
+		return err
+	}
+	// Reject trailing junk so a half-edited file (two objects, leftover
+	// fragment) cannot look like it loaded successfully.
+	if _, err := dec.Token(); !errors.Is(err, io.EOF) {
+		return errors.New("unexpected trailing data after the JSON object")
+	}
+	return nil
+}
+
+// Load reads path and returns the merged+expanded config.
+//
+// A missing file is NOT an error: (nil, nil) tells the caller to fall back to
+// pure flag behaviour. Anything else — unreadable, malformed JSON, unknown
+// key, trailing junk, undefined ${VAR}, unreadable file: reference — is
+// returned as an error, which main() turns into a fatal exit.
+func Load(path string) (*File, error) {
+	raw, err := os.ReadFile(path)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return nil, nil
+		}
+		return nil, fmt.Errorf("config file %s: read: %w", path, err)
+	}
+	var f File
+	if err := decodeStrict(raw, &f); err != nil {
+		return nil, fmt.Errorf("config file %s: invalid JSON: %w (known keys: addr, user, password, workdir, bin, frpc, peers, join_key; keys starting with \"_\" are ignored)", path, err)
+	}
+	if f.JoinKey == "" {
+		f.JoinKey = f.JoinKeyCamel
+	}
+	if err := expandAll(&f); err != nil {
+		return nil, fmt.Errorf("config file %s: %w", path, err)
+	}
+	return &f, nil
+}
+
+// expand resolves ${VAR} / $VAR and a leading file: reference. $${...} and $$
+// produce a literal '$'.
+//
+// An undefined or empty environment variable is an error rather than an empty
+// expansion: booting with an empty password looks like "wrong password" later
+// and leaves the node unauthenticated in the meantime.
+func expand(s string) (string, error) {
+	var missing []string
+	out := os.Expand(s, func(name string) string {
+		if name == "$" { // "$$" escapes a literal dollar sign
+			return "$"
+		}
+		v, ok := os.LookupEnv(name)
+		if !ok || v == "" {
+			missing = append(missing, name)
+			return ""
+		}
+		return v
+	})
+	if len(missing) > 0 {
+		return "", fmt.Errorf("undefined environment variable(s): %s (use $$ for a literal $)", strings.Join(missing, ", "))
+	}
+	if strings.HasPrefix(out, "file:") {
+		p := strings.TrimPrefix(out, "file:")
+		if p == "" {
+			return "", errors.New("file: reference with an empty path")
+		}
+		raw, err := os.ReadFile(p)
+		if err != nil {
+			return "", fmt.Errorf("file reference %q: %w", out, err)
+		}
+		// Secrets files are conventionally "one value, one newline"; take the
+		// first line so a trailing comment/newline cannot corrupt the value.
+		line, _, _ := strings.Cut(string(raw), "\n")
+		return strings.TrimRight(line, "\r"), nil
+	}
+	return out, nil
+}
+
+func expandAll(f *File) error {
+	fields := []struct {
+		name string
+		ptr  *string
+	}{
+		{"addr", &f.Addr},
+		{"user", &f.User},
+		{"password", &f.Password},
+		{"workdir", &f.WorkDir},
+		{"bin", &f.Bin},
+		{"frpc", &f.FRPC},
+		{"join_key", &f.JoinKey},
+	}
+	for _, fd := range fields {
+		raw := *fd.ptr
+		v, err := expand(raw)
+		if err != nil {
+			return fmt.Errorf("field %s: %w", fd.name, err)
+		}
+		*fd.ptr = v
+	}
+	for i, p := range f.Peers {
+		v, err := expand(p)
+		if err != nil {
+			return fmt.Errorf("peers[%d]: %w", i, err)
+		}
+		f.Peers[i] = v
+	}
+	return nil
+}
+
+// DefaultPath is the config file used when -config is not given:
+// <workdir>/config.json. workdir here is the *flag* value (explicit or
+// built-in default) because the file must be locatable before it can be
+// parsed — a workdir that only appears inside the file cannot move it.
+func DefaultPath(workdir string) string { return filepath.Join(workdir, "config.json") }
--- a/internal/appconfig/appconfig_test.go
+++ b/internal/appconfig/appconfig_test.go
@ -0,0 +1,317 @@
+package appconfig
+
+import (
+	"encoding/json"
+	"flag"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func write(t *testing.T, dir, name, body string) string {
+	t.Helper()
+	p := filepath.Join(dir, name)
+	if err := os.WriteFile(p, []byte(body), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	return p
+}
+
+func TestLoadMissingFileIsNotAnError(t *testing.T) {
+	f, err := Load(filepath.Join(t.TempDir(), "nope.json"))
+	if err != nil {
+		t.Fatalf("missing file must not error, got %v", err)
+	}
+	if f != nil {
+		t.Fatalf("missing file must yield nil config, got %+v", f)
+	}
+}
+
+func TestLoadRejectsBadJSON(t *testing.T) {
+	dir := t.TempDir()
+	for name, body := range map[string]string{
+		"truncated.json": `{"addr": "0.0.0.0:7500"`,
+		"trailing.json":  `{"addr":"a"}{"addr":"b"}`,
+		"garbage.json":   `not json at all`,
+	} {
+		p := write(t, dir, name, body)
+		if _, err := Load(p); err == nil {
+			t.Errorf("%s: expected a loud parse error, got nil", name)
+		}
+	}
+}
+
+func TestLoadRejectsUnknownKey(t *testing.T) {
+	// A typo like "passwd" must not silently leave the password at its default.
+	p := write(t, t.TempDir(), "c.json", `{"passwd": "x"}`)
+	if _, err := Load(p); err == nil {
+		t.Fatal("unknown key must be rejected")
+	}
+}
+
+func TestLoadExpandsEnv(t *testing.T) {
+	t.Setenv("W4F_TEST_PASSWORD", "s3cret")
+	p := write(t, t.TempDir(), "c.json", `{"password": "${W4F_TEST_PASSWORD}", "user": "u"}`)
+	f, err := Load(p)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if f.Password != "s3cret" {
+		t.Fatalf("password not expanded: %q", f.Password)
+	}
+}
+
+func TestLoadUndefinedEnvIsAnError(t *testing.T) {
+	// Secrets are normally behind ${VAR}; an unset var must fail instead of
+	// booting with an empty password.
+	p := write(t, t.TempDir(), "c.json", `{"password": "${W4F_DEFINITELY_UNSET}"}`)
+	os.Unsetenv("W4F_DEFINITELY_UNSET")
+	_, err := Load(p)
+	if err == nil {
+		t.Fatal("undefined env var must error")
+	}
+	if !strings.Contains(err.Error(), "W4F_DEFINITELY_UNSET") {
+		t.Fatalf("error should name the variable: %v", err)
+	}
+}
+
+func TestLoadFileReference(t *testing.T) {
+	dir := t.TempDir()
+	secret := write(t, dir, "pw", "from-file\nignored-second-line\n")
+	p := write(t, dir, "c.json", `{"password": "file:`+secret+`"}`)
+	f, err := Load(p)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if f.Password != "from-file" {
+		t.Fatalf("file: reference = %q, want first line only", f.Password)
+	}
+}
+
+func TestLoadMissingFileReferenceIsAnError(t *testing.T) {
+	p := write(t, t.TempDir(), "c.json", `{"password": "file:/nonexistent/secret"}`)
+	if _, err := Load(p); err == nil {
+		t.Fatal("unreadable file: reference must error")
+	}
+}
+
+func TestLoadJoinKeyAlias(t *testing.T) {
+	p := write(t, t.TempDir(), "c.json", `{"joinKey": "k1"}`)
+	f, err := Load(p)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if f.JoinKey != "k1" {
+		t.Fatalf("joinKey alias not honoured: %q", f.JoinKey)
+	}
+}
+
+func TestLoadPeersExpanded(t *testing.T) {
+	t.Setenv("W4F_TEST_HOST", "10.0.0.2")
+	p := write(t, t.TempDir(), "c.json", `{"peers": ["${W4F_TEST_HOST}:7500", "10.0.0.3:7500"]}`)
+	f, err := Load(p)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(f.Peers) != 2 || f.Peers[0] != "10.0.0.2:7500" || f.Peers[1] != "10.0.0.3:7500" {
+		t.Fatalf("peers = %v", f.Peers)
+	}
+}
+
+// parseFlags parses args on a fresh FlagSet with the same defaults as main,
+// so ExplicitSet sees exactly what the operator typed.
+func parseFlags(t *testing.T, args ...string) (Values, map[string]bool) {
+	t.Helper()
+	fs := flag.NewFlagSet("test", flag.ContinueOnError)
+	addr := fs.String("addr", "127.0.0.1:7500", "")
+	user := fs.String("user", "admin", "")
+	pass := fs.String("password", "admin", "")
+	workdir := fs.String("workdir", "./webui-frpc", "")
+	bin := fs.String("bin", "", "")
+	frpc := fs.String("frpc", "", "")
+	joinKey := fs.String("join-key", "", "")
+	var peers multi
+	fs.Var(&peers, "peer", "")
+	if err := fs.Parse(args); err != nil {
+		t.Fatal(err)
+	}
+	return Values{
+		Addr: *addr, User: *user, Password: *pass, WorkDir: *workdir,
+		Bin: *bin, FRPC: *frpc, Peers: peers, JoinKey: *joinKey,
+	}, ExplicitSet(fs)
+}
+
+type multi []string
+
+func (m *multi) String() string     { return strings.Join(*m, ",") }
+func (m *multi) Set(v string) error { *m = append(*m, v); return nil }
+
+var defs = Defaults{Addr: "127.0.0.1:7500", User: "admin", Password: "admin", WorkDir: "./webui-frpc"}
+
+// This is THE regression test for the task's main pitfall: with no flags
+// passed, Go's flag defaults must not win over the config file.
+func TestResolveFileBeatsFlagDefaults(t *testing.T) {
+	flags, explicit := parseFlags(t) // no args at all
+	f := &File{Addr: "0.0.0.0:7500", User: "jianf", Password: "pw", WorkDir: "/var/lib/webui4frpc",
+		Bin: "/opt/frpc", FRPC: "/opt/frpc2", Peers: []string{"1.2.3.4:7500"}, JoinKey: "k"}
+	v, src := Resolve(defs, flags, explicit, f)
+
+	if v.Addr != "0.0.0.0:7500" || v.User != "jianf" || v.Password != "pw" || v.WorkDir != "/var/lib/webui4frpc" {
+		t.Fatalf("file values lost to flag defaults: %+v", v)
+	}
+	if v.Bin != "/opt/frpc" || v.FRPC != "/opt/frpc2" || v.JoinKey != "k" || len(v.Peers) != 1 {
+		t.Fatalf("file optional values lost: %+v", v)
+	}
+	for name, got := range map[string]string{"addr": src.Addr, "user": src.User, "password": src.Password, "workdir": src.WorkDir} {
+		if got != SourceFile {
+			t.Errorf("%s source = %q, want file", name, got)
+		}
+	}
+}
+
+func TestResolveExplicitFlagBeatsFile(t *testing.T) {
+	flags, explicit := parseFlags(t, "-addr", "127.0.0.1:9000", "-password", "cli-pw")
+	f := &File{Addr: "0.0.0.0:7500", Password: "file-pw"}
+	v, src := Resolve(defs, flags, explicit, f)
+	if v.Addr != "127.0.0.1:9000" {
+		t.Fatalf("explicit -addr ignored: %q", v.Addr)
+	}
+	if v.Password != "cli-pw" {
+		t.Fatalf("explicit -password ignored: %q", v.Password)
+	}
+	if src.Addr != SourceFlag || src.Password != SourceFlag {
+		t.Fatalf("sources = %+v", src)
+	}
+}
+
+func TestResolveDefaultsWhenNoFile(t *testing.T) {
+	flags, explicit := parseFlags(t)
+	v, src := Resolve(defs, flags, explicit, nil)
+	if v.Addr != "127.0.0.1:7500" || v.User != "admin" || v.Password != "admin" || v.WorkDir != "./webui-frpc" {
+		t.Fatalf("defaults not applied: %+v", v)
+	}
+	if src.Password != SourceDefault {
+		t.Fatalf("password source = %q, want default", src.Password)
+	}
+}
+
+func TestResolveEmptyFileFieldFallsBackToDefault(t *testing.T) {
+	flags, explicit := parseFlags(t)
+	f := &File{Addr: "0.0.0.0:7500"} // no user/password/workdir
+	v, src := Resolve(defs, flags, explicit, f)
+	if v.User != "admin" || v.Password != "admin" || v.WorkDir != "./webui-frpc" {
+		t.Fatalf("absent file fields must fall back to defaults: %+v", v)
+	}
+	if src.User != SourceDefault {
+		t.Fatalf("user source = %q", src.User)
+	}
+}
+
+func TestResolvePeerFlagReplacesFileList(t *testing.T) {
+	flags, explicit := parseFlags(t, "-peer", "9.9.9.9:7500")
+	f := &File{Peers: []string{"1.1.1.1:7500", "2.2.2.2:7500"}}
+	v, _ := Resolve(defs, flags, explicit, f)
+	if len(v.Peers) != 1 || v.Peers[0] != "9.9.9.9:7500" {
+		t.Fatalf("explicit -peer must replace the file list, got %v", v.Peers)
+	}
+}
+
+// The password and join key must never appear in anything we log.
+func TestSummaryRedactsSecrets(t *testing.T) {
+	v := Values{
+		Addr: "0.0.0.0:7500", User: "jianf", Password: "sup3rs3cret",
+		WorkDir: "/var/lib/webui4frpc", JoinKey: "joinkey-value",
+	}
+	for _, s := range []string{v.Summary(), v.String()} {
+		if strings.Contains(s, "sup3rs3cret") {
+			t.Fatalf("password leaked into summary: %s", s)
+		}
+		if strings.Contains(s, "joinkey-value") {
+			t.Fatalf("join key leaked into summary: %s", s)
+		}
+		if !strings.Contains(s, "0.0.0.0:7500") || !strings.Contains(s, "jianf") {
+			t.Fatalf("summary dropped non-secret fields: %s", s)
+		}
+	}
+	// %v must go through String() as well.
+	if strings.Contains(strings.Join([]string{v.Summary()}, ""), "sup3rs3cret") {
+		t.Fatal("leak")
+	}
+}
+
+func TestDefaultPath(t *testing.T) {
+	if got := DefaultPath("/var/lib/webui4frpc"); got != "/var/lib/webui4frpc/config.json" {
+		t.Fatalf("DefaultPath = %q", got)
+	}
+}
+
+// Sample files carry "_comment"/"_optional" documentation keys; they must load
+// without weakening the unknown-key check for real fields.
+func TestLoadIgnoresCommentKeys(t *testing.T) {
+	p := write(t, t.TempDir(), "c.json", `{"_comment": ["doc"], "_optional": ["more doc"], "addr": "0.0.0.0:7500"}`)
+	f, err := Load(p)
+	if err != nil {
+		t.Fatalf("underscore comment keys must be ignored, got %v", err)
+	}
+	if f.Addr != "0.0.0.0:7500" {
+		t.Fatalf("addr = %q", f.Addr)
+	}
+}
+
+// The shipped example must actually be loadable, otherwise the documented
+// "copy this file" path fails at first start. It references a secrets file that
+// does not exist in a test environment, so only the schema is checked here by
+// rewriting the password to a literal.
+func TestShippedSampleConfigParses(t *testing.T) {
+	raw, err := os.ReadFile("../../packaging/common/config.json")
+	if err != nil {
+		t.Skipf("sample not found: %v", err)
+	}
+	var probe map[string]any
+	if err := json.Unmarshal(raw, &probe); err != nil {
+		t.Fatalf("sample config is not valid JSON: %v", err)
+	}
+	// Remove the file: reference (no /etc secrets in tests) and reload through
+	// the real loader so schema drift is caught.
+	probe["password"] = "literal"
+	dir := t.TempDir()
+	p := filepath.Join(dir, "config.json")
+	out, _ := json.Marshal(probe)
+	if err := os.WriteFile(p, out, 0o600); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := Load(p); err != nil {
+		t.Fatalf("shipped sample config rejected: %v", err)
+	}
+}
+
+// -join-key's flag default comes from $W4F_JOIN_KEY; when the operator does not
+// type the flag, that environment value must still win over the config file
+// (it is the more specific, per-process setting).
+func TestResolveJoinKeyEnvBeatsFile(t *testing.T) {
+	flags, explicit := parseFlags(t) // not passed on the command line
+	flags.JoinKey = "env-key"
+	v, src := Resolve(defs, flags, explicit, &File{JoinKey: "file-key"})
+	if v.JoinKey != "env-key" {
+		t.Fatalf("env join key lost: %q", v.JoinKey)
+	}
+	if src.JoinKey != SourceEnv {
+		t.Fatalf("source = %q, want env", src.JoinKey)
+	}
+
+	// Explicit flag still wins over both.
+	flags, explicit = parseFlags(t, "-join-key", "cli-key")
+	flags.JoinKey = "cli-key"
+	v, _ = Resolve(defs, flags, explicit, &File{JoinKey: "file-key"})
+	if v.JoinKey != "cli-key" {
+		t.Fatalf("explicit -join-key ignored: %q", v.JoinKey)
+	}
+
+	// No env, no flag -> the file value is used.
+	flags, explicit = parseFlags(t)
+	v, src = Resolve(defs, flags, explicit, &File{JoinKey: "file-key"})
+	if v.JoinKey != "file-key" || src.JoinKey != SourceFile {
+		t.Fatalf("file join key not used: %q (%s)", v.JoinKey, src.JoinKey)
+	}
+}
--- a/internal/appconfig/resolve.go
+++ b/internal/appconfig/resolve.go
@ -0,0 +1,140 @@
+package appconfig
+
+import (
+	"flag"
+	"fmt"
+	"strings"
+)
+
+// Field sources, for logging only — never for values.
+const (
+	SourceFlag    = "flag"
+	SourceEnv     = "env"
+	SourceFile    = "file"
+	SourceDefault = "default"
+)
+
+// Defaults are the built-in defaults, i.e. exactly what the flags declare.
+type Defaults struct {
+	Addr     string
+	User     string
+	Password string
+	WorkDir  string
+}
+
+// Values is the effective runtime configuration after merging.
+type Values struct {
+	Addr     string
+	User     string
+	Password string
+	WorkDir  string
+	Bin      string
+	FRPC     string
+	Peers    []string
+	JoinKey  string
+}
+
+// Sources records where each resolved field came from ("" = not configured).
+type Sources struct {
+	Addr     string
+	User     string
+	Password string
+	WorkDir  string
+	Bin      string
+	FRPC     string
+	Peers    string
+	JoinKey  string
+}
+
+// ExplicitSet returns the flag names the operator actually typed.
+//
+// flag.Visit walks only flags that were set on the command line, which is
+// precisely the test required here: an unset flag must NOT override a config
+// file value with its default.
+func ExplicitSet(fs *flag.FlagSet) map[string]bool {
+	set := map[string]bool{}
+	fs.Visit(func(f *flag.Flag) { set[f.Name] = true })
+	return set
+}
+
+// Resolve merges per field: explicit flag > config file (non-empty) >
+// built-in default.
+func Resolve(def Defaults, flags Values, explicit map[string]bool, f *File) (Values, Sources) {
+	var out Values
+	var src Sources
+	var file File
+	if f != nil {
+		file = *f
+	}
+
+	// pick covers the four fields that have a built-in default.
+	pick := func(flagName, flagVal, defVal, fileVal string) (string, string) {
+		if explicit[flagName] {
+			return flagVal, SourceFlag
+		}
+		if fileVal != "" {
+			return fileVal, SourceFile
+		}
+		return defVal, SourceDefault
+	}
+
+	out.Addr, src.Addr = pick("addr", flags.Addr, def.Addr, file.Addr)
+	out.User, src.User = pick("user", flags.User, def.User, file.User)
+	out.Password, src.Password = pick("password", flags.Password, def.Password, file.Password)
+	out.WorkDir, src.WorkDir = pick("workdir", flags.WorkDir, def.WorkDir, file.WorkDir)
+
+	// No built-in default for these: empty means "not configured".
+	pickOpt := func(flagName, flagVal, fileVal string) (string, string) {
+		if explicit[flagName] {
+			return flagVal, SourceFlag
+		}
+		if fileVal != "" {
+			return fileVal, SourceFile
+		}
+		return "", ""
+	}
+	out.Bin, src.Bin = pickOpt("bin", flags.Bin, file.Bin)
+	out.FRPC, src.FRPC = pickOpt("frpc", flags.FRPC, file.FRPC)
+
+	// join-key is special: its flag default comes from $W4F_JOIN_KEY, i.e. a
+	// per-process override that is more specific than a value baked into the
+	// config file. Dropping it here would silently disable env-based cluster
+	// joining whenever a file happened to be present.
+	switch {
+	case explicit["join-key"]:
+		out.JoinKey, src.JoinKey = flags.JoinKey, SourceFlag
+	case flags.JoinKey != "":
+		out.JoinKey, src.JoinKey = flags.JoinKey, SourceEnv
+	case file.JoinKey != "":
+		out.JoinKey, src.JoinKey = file.JoinKey, SourceFile
+	}
+
+	// peers is repeatable (-peer a -peer b). An explicit flag REPLACES the
+	// file's list instead of appending: appending would resurrect peers the
+	// operator deliberately dropped on the command line.
+	if explicit["peer"] {
+		out.Peers, src.Peers = flags.Peers, SourceFlag
+	} else if len(file.Peers) > 0 {
+		out.Peers, src.Peers = file.Peers, SourceFile
+	}
+	return out, src
+}
+
+// Summary renders the resolved configuration for the startup log with every
+// secret redacted. Using this instead of ad-hoc formatting means an accidental
+// log.Printf("%v", values) still cannot leak the basic-auth password or the
+// cluster join key.
+func (v Values) Summary() string {
+	return fmt.Sprintf("addr=%s user=%s password=<redacted> workdir=%s bin=%s frpc=%s peers=%s join-key=<redacted>",
+		v.Addr, v.User, v.WorkDir, orDash(v.Bin), orDash(v.FRPC), orDash(strings.Join(v.Peers, ",")))
+}
+
+func orDash(s string) string {
+	if s == "" {
+		return "-"
+	}
+	return s
+}
+
+// String implements fmt.Stringer so %v/%s on Values is always redacted.
+func (v Values) String() string { return v.Summary() }
--- a/internal/cluster/balance_test.go
+++ b/internal/cluster/balance_test.go
@ -0,0 +1,728 @@
+package cluster
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	"webui4frpc/internal/store"
+)
+
+// mustState round-trips the seed through JSON so the engine under test owns its
+// own copy of Nodes/Topology. AdoptState assigns the state by value, but Nodes is
+// a slice: handing one seed to several engines would alias one backing array and
+// make a mutation on one node visible on the others — a test artefact that
+// previously produced a false green here.
+func mustState(t *testing.T, s State) *State {
+	t.Helper()
+	b, err := json.Marshal(s)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var out State
+	if err := json.Unmarshal(b, &out); err != nil {
+		t.Fatal(err)
+	}
+	e := newTestEngine("probe", true)
+	e.AdoptState(out)
+	return e.State()
+}
+
+// migrateRing builds a 3-node ring where n1 owns every forward, plus n2/n3 idle.
+func migrateRing(t *testing.T, ownCount int) (*Engine, *Engine, *Engine) {
+	t.Helper()
+	mk := func(id string, leader bool) *Engine {
+		h := &fakeHandler{load: Load{MemPct: 5, NetPct: 5}}
+		return NewEngine(id, id+":7500", "u", "p", "0.1.3", nil, h,
+			func(ctx context.Context, next string, tk *Token) error { return nil },
+			id+":7500", leader, "")
+	}
+	n1, n2, n3 := mk("n1", true), mk("n2", false), mk("n3", false)
+
+	seed := State{
+		LeaderID: "n1",
+		Nodes: []Node{
+			{ID: "n1", Addr: "n1:7500", Alive: true, IsLeader: true, Load: Load{Forwards: ownCount, MemPct: 5}},
+			{ID: "n2", Addr: "n2:7500", Alive: true, Load: Load{MemPct: 5}},
+			{ID: "n3", Addr: "n3:7500", Alive: true, Load: Load{MemPct: 5}},
+		},
+		Topology:     map[string]*TopoEntry{},
+		PendingTasks: map[string]*Task{},
+	}
+	for _, e := range []*Engine{n1, n2, n3} {
+		var own State
+		b, _ := json.Marshal(seed)
+		if err := json.Unmarshal(b, &own); err != nil {
+			t.Fatal(err)
+		}
+		e.AdoptState(own)
+	}
+	// n1 claims `ownCount` forwards.
+	for i := 0; i < ownCount; i++ {
+		n1.state.AddTopology(&Task{
+			ID:    "f" + string(rune('a'+i)),
+			Local: store.Local{Name: "web"}, Remote: store.Remote{Name: "frps1"},
+			Link: store.Link{RemotePort: 100 + i},
+		}, "n1")
+	}
+	var snap State
+	b, _ := json.Marshal(n1.state)
+	_ = json.Unmarshal(b, &snap)
+	for _, e := range []*Engine{n1, n2, n3} {
+		e.AdoptState(snap)
+	}
+	return n1, n2, n3
+}
+
+// errNotWritable stands in for a failing settings write.
+var errNotWritable = errors.New("not writable")
+
+// ---- helpers ----
+
+// balanceRing builds a 3-node ring with `owned` forwards on n1 (the evaluation
+// node) and `others` on each of the other two, so a test can set up any
+// distribution directly. The replicated Nodes[].Load is made consistent with the
+// topology, because that is what a real token round leaves behind.
+func balanceRing(t *testing.T, owned, others int) (*Engine, *Engine, *Engine) {
+	t.Helper()
+	mk := func(id string, leader bool) *Engine {
+		h := &fakeHandler{load: Load{MemPct: 5, NetPct: 5}}
+		return NewEngine(id, id+":7500", "u", "p", "0.1.3", nil, h,
+			func(ctx context.Context, next string, tk *Token) error { return nil },
+			id+":7500", leader, "")
+	}
+	n1, n2, n3 := mk("n1", true), mk("n2", false), mk("n3", false)
+
+	seed := State{
+		LeaderID: "n1",
+		Nodes: []Node{
+			{ID: "n1", Addr: "n1:7500", Alive: true, IsLeader: true, Load: Load{Forwards: owned, MemPct: 5}},
+			{ID: "n2", Addr: "n2:7500", Alive: true, Load: Load{Forwards: others, MemPct: 5}},
+			{ID: "n3", Addr: "n3:7500", Alive: true, Load: Load{Forwards: others, MemPct: 5}},
+		},
+		Topology:     map[string]*TopoEntry{},
+		PendingTasks: map[string]*Task{},
+	}
+	for _, e := range []*Engine{n1, n2, n3} {
+		var own State
+		b, _ := json.Marshal(seed)
+		if err := json.Unmarshal(b, &own); err != nil {
+			t.Fatal(err)
+		}
+		e.AdoptState(own)
+	}
+	// Build the whole topology in n1's state, then broadcast it. Adding each
+	// node's forwards to its OWN state and then re-adopting from n1 would discard
+	// the others (one state is the source of the broadcast), which is how an
+	// earlier version of this helper silently produced a 1-1-1 split regardless
+	// of the arguments.
+	add := func(owner, prefix string, count, basePort int) {
+		for i := 0; i < count; i++ {
+			n1.state.AddTopology(&Task{
+				ID:    prefix + strconv.Itoa(i),
+				Local: store.Local{Name: "web"}, Remote: store.Remote{Name: "frps1"},
+				Link: store.Link{RemotePort: basePort + i},
+			}, owner)
+		}
+	}
+	add("n1", "f", owned, 100)
+	add("n2", "g", others, 200)
+	add("n3", "h", others, 300)
+
+	var snap State
+	b, _ := json.Marshal(n1.state)
+	_ = json.Unmarshal(b, &snap)
+	for _, e := range []*Engine{n1, n2, n3} {
+		e.AdoptState(snap)
+	}
+	return n1, n2, n3
+}
+
+// ---- the rule ----
+
+// TestShareIsTheEvenSplit pins the arithmetic, including the ceiling. An even
+// split of 3 over 3 is 1 (not 1.0 floored to 0): with a floor, a node holding
+// one of three forwards would still be "over its share" and shed it.
+func TestShareIsTheEvenSplit(t *testing.T) {
+	for _, tc := range []struct{ total, alive, want int }{
+		{3, 3, 1}, {4, 3, 2}, {6, 2, 3}, {1, 3, 1}, {0, 3, 0}, {7, 3, 3},
+	} {
+		got := (tc.total + tc.alive - 1) / tc.alive
+		if got != tc.want {
+			t.Errorf("share(%d over %d) = %d, want %d", tc.total, tc.alive, got, tc.want)
+		}
+	}
+}
+
+// TestOwnerReleasesWhenOverItsShare: 3 forwards on n1, none elsewhere → n1 holds
+// 3 against a share of 1 and must give one up.
+func TestOwnerReleasesWhenOverItsShare(t *testing.T) {
+	n1, _, _ := balanceRing(t, 3, 0)
+	b := NewBalancer(n1, 0)
+
+	pick, p, blocked := b.assess(1000)
+	if pick == nil {
+		t.Fatalf("n1 holds 3 of 3 forwards and should release one (blocked=%q)", blocked)
+	}
+	if blocked != "" {
+		t.Errorf("nothing should block the first release, got %q", blocked)
+	}
+	if p.mine != 3 || p.share != 1 || p.total != 3 || p.alive != 3 {
+		t.Errorf("pool = %+v, want mine=3 share=1 total=3 alive=3", p)
+	}
+	if pick.OwnerID != "n1" {
+		t.Errorf("must release a forward n1 owns, got owner %q", pick.OwnerID)
+	}
+}
+
+// TestReleasingStopsAtTheShare is the bound that keeps the rule from emptying a
+// node: after shedding one, n1 holds 1 of 3 over 3 nodes, which is no longer more
+// than the share, and it must stop.
+func TestReleasingStopsAtTheShare(t *testing.T) {
+	n1, _, _ := balanceRing(t, 1, 1) // even 1-1-1 split
+	b := NewBalancer(n1, 0)
+
+	pick, p, blocked := b.assess(1000)
+	if pick != nil {
+		t.Errorf("an even 1-1-1 split must not release anything, got %s:%d (blocked=%q)",
+			pick.Local.Name, pick.Link.RemotePort, blocked)
+	}
+	if p.mine != 1 || p.share != 1 {
+		t.Errorf("pool = %+v, want mine=1 share=1", p)
+	}
+}
+
+// TestSingleNodeNeverReleases: a standalone node is the whole cluster, so its
+// share is everything it holds. Without this the node would shed forwards onto
+// nobody (they would sit unclaimed until it re-claimed them).
+func TestSingleNodeNeverReleases(t *testing.T) {
+	e := newTestEngine("solo", true)
+	e.state.Nodes = []Node{{ID: "solo", Addr: "solo:7500", Alive: true, IsLeader: true}}
+	for i := 0; i < 5; i++ {
+		e.state.AddTopology(&Task{
+			ID: "f" + strconv.Itoa(i), Local: store.Local{Name: "web"},
+			Remote: store.Remote{Name: "frps1"}, Link: store.Link{RemotePort: 100 + i},
+		}, "solo")
+	}
+	b := NewBalancer(e, 0)
+	if pick, _, blocked := b.assess(1000); pick != nil {
+		t.Errorf("a single-node ring must not release; got blocked=%q", blocked)
+	}
+}
+
+// TestBelowFloorNeverReleases: two forwards on a node is the floor. A node
+// holding exactly two at an even split of two must keep both — one release per
+// node per pass is the granularity, and shedding below the floor would empty it.
+func TestBelowFloorNeverReleases(t *testing.T) {
+	n1, _, _ := balanceRing(t, 2, 2) // 6 total over 3 nodes → share 2
+	b := NewBalancer(n1, 0)
+	if pick, p, blocked := b.assess(1000); pick != nil {
+		t.Errorf("2 owned against share %d must not release (blocked=%q, mine=%d)",
+			p.share, blocked, p.mine)
+	}
+}
+
+// TestNeverReleasesAStoppedForward: a stopped forward's entry is the carrier of
+// the user's stop decision. Releasing it would hand another node a STOPPED
+// forward as if it were work to run.
+func TestNeverReleasesAStoppedForward(t *testing.T) {
+	n1, _, _ := balanceRing(t, 3, 0)
+	// Stop two of n1's three; the only live one must be chosen.
+	for _, te := range n1.state.ForwardsOwnedBy("n1") {
+		if te.Link.RemotePort == 100 || te.Link.RemotePort == 101 {
+			n1.state.UpdateTopologyDisabled("web", "frps1", te.Link.RemotePort, true)
+		}
+	}
+	b := NewBalancer(n1, 0)
+	pick, _, _ := b.assess(1000)
+	if pick == nil {
+		t.Fatal("n1 still owns one live forward and is over its share")
+	}
+	if pick.Link.RemotePort != 102 {
+		t.Errorf("released port %d; a stopped forward (100/101) must never be chosen",
+			pick.Link.RemotePort)
+	}
+
+	// And with every forward stopped there is nothing to release.
+	n1.state.UpdateTopologyDisabled("web", "frps1", 102, true)
+	if pick, _, blocked := b.assess(1000); pick != nil {
+		t.Errorf("all forwards stopped: nothing may be released (blocked=%q)", blocked)
+	}
+}
+
+// TestCandidateChoiceIsDeterministic: the same state must pick the same forward,
+// so the decision is explainable and a re-evaluation does not churn a different
+// connection each tick.
+func TestCandidateChoiceIsDeterministic(t *testing.T) {
+	n1, _, _ := balanceRing(t, 4, 0)
+	a := releaseCandidate(n1.State(), "n1")
+	c := releaseCandidate(n1.State(), "n1")
+	if a == nil || c == nil {
+		t.Fatal("expected a candidate")
+	}
+	if a.TaskID != c.TaskID || a.Link.RemotePort != c.Link.RemotePort {
+		t.Errorf("candidate changed between identical evaluations: %s:%d vs %s:%d",
+			a.TaskID, a.Link.RemotePort, c.TaskID, c.Link.RemotePort)
+	}
+	if a.Link.RemotePort != 100 {
+		t.Errorf("expected the lowest port (100), got %d", a.Link.RemotePort)
+	}
+}
+
+// ---- the runtime signal that makes this safe ----
+
+// TestRevokeLeavesACarrierAndReleaseRemovesIt is the reason the release path has
+// to be a distinct task kind.
+//
+// A user stop keeps the topology entry as the carrier of the disabled flag, so
+// the entry is STILL THERE and still attributed to the owner. A rebalance is the
+// opposite: the entry must go, because (a) the node's load is derived from
+// owned entries so it cannot fall while the entry exists, and (b) every node's
+// duplicate guard refuses a creation task for a forward that already has an owner
+// — so the re-published task would be dropped by everyone and the forward
+// stranded on the node that gave it up.
+func TestRevokeLeavesACarrierAndReleaseRemovesIt(t *testing.T) {
+	n1, _, _ := balanceRing(t, 3, 0)
+
+	// A stop marks the entry and keeps it.
+	n1.state.UpdateTopologyDisabled("web", "frps1", 100, true)
+	tk := &Task{Local: store.Local{Name: "web"}, Remote: store.Remote{Name: "frps1"},
+		Link: store.Link{RemotePort: 100}}
+	if owner := n1.state.TopologyOwner(tk); owner != "n1" {
+		t.Fatalf("a stop must keep the entry as the flag's carrier, owner=%q", owner)
+	}
+	if got := len(n1.state.ForwardsOwnedBy("n1")); got != 3 {
+		t.Fatalf("a stop must not change the owner's forward count, got %d", got)
+	}
+
+	// A release removes the entry (leaving the other two alone).
+	if !n1.RemoveTopologyEntry("web", "frps1", 100) {
+		t.Fatal("release must remove the entry")
+	}
+	if owner := n1.state.TopologyOwner(tk); owner != "" {
+		t.Errorf("after a release the forward must have no owner, got %q", owner)
+	}
+	if got := len(n1.state.ForwardsOwnedBy("n1")); got != 2 {
+		t.Errorf("a release must reduce the owner's count, got %d", got)
+	}
+	if got := len(n1.state.TopologyList()); got != 2 {
+		t.Errorf("the other forwards must be untouched, got %d entries", got)
+	}
+}
+
+// TestReleaseTaskExecutesOnlyOnTheOwner: like a revoke, a release is
+// owner-directed. Executing it elsewhere would be an attempt to move somebody
+// else's load, which cannot work — the owner's own count is what must fall.
+func TestReleaseTaskExecutesOnlyOnTheOwner(t *testing.T) {
+	n1, n2, _ := balanceRing(t, 3, 0)
+
+	released := map[string]int{}
+	for _, e := range []*Engine{n1, n2} {
+		h := e.Handler.(*fakeHandler)
+		h.release = func(ctx context.Context, tk *Task) error {
+			released[e.ID]++
+			return nil
+		}
+	}
+	tk := n1.ReleaseTask(store.Local{Name: "web"}, store.Remote{Name: "frps1"},
+		store.Link{RemotePort: 100})
+	if tk == nil {
+		t.Fatal("ReleaseTask returned nil")
+	}
+
+	// Each Engine keeps its OWN state, so a task published on n1 is not visible
+	// to n2 until a token round carries it. Broadcast it the way the ring does.
+	var carry State
+	cb, _ := json.Marshal(n1.state)
+	_ = json.Unmarshal(cb, &carry)
+	n2.AdoptState(carry)
+	n2.state.PendingTasks[tk.ID] = tk
+
+	// n2 is the lightest node and does NOT own the forward: it must leave the
+	// task alone.
+	if err := n2.runCommands(context.Background(), &Token{}); err != nil {
+		t.Fatalf("n2 runCommands: %v", err)
+	}
+	if released["n2"] != 0 {
+		t.Errorf("n2 released %d forward(s); a release is owner-directed only", released["n2"])
+	}
+	if _, still := n2.state.PendingTasks[tk.ID]; !still {
+		t.Error("n2 consumed a release it does not own; it must ride the token to the owner")
+	}
+
+	// n1 owns it: it must release, drop the entry, and re-publish the forward.
+	if err := n1.runCommands(context.Background(), &Token{}); err != nil {
+		t.Fatalf("n1 runCommands: %v", err)
+	}
+	if released["n1"] != 1 {
+		t.Fatalf("the owner released %d times, want 1", released["n1"])
+	}
+	if owner := n1.state.TopologyOwner(&Task{
+		Local: store.Local{Name: "web"}, Remote: store.Remote{Name: "frps1"},
+		Link: store.Link{RemotePort: 100},
+	}); owner != "" {
+		t.Errorf("the released forward still has owner %q", owner)
+	}
+	// And it is back in the ring as an ordinary creation task.
+	var republished *Task
+	for _, p := range n1.state.PendingList() {
+		if !p.Release && !p.Revoke && !p.Restart &&
+			p.Link.RemotePort == 100 && p.Local.Name == "web" {
+			republished = p
+		}
+	}
+	if republished == nil {
+		t.Fatal("the released forward was not re-published as an unclaimed task")
+	}
+	if republished.Link.Disabled {
+		t.Error("the re-published forward must be ENABLED, not marked stopped")
+	}
+}
+
+// ---- dry-run / off ----
+
+// TestDryRunReleasesNothing: dry-run is the default, and its whole value is that
+// it can run on a live cluster without disturbing anything.
+func TestDryRunReleasesNothing(t *testing.T) {
+	n1, _, _ := balanceRing(t, 3, 0)
+	b := NewBalancer(n1, 0)
+	b.SetMode(BalanceDryRun)
+
+	msg := b.Step(1000)
+	if !strings.Contains(msg, "would release") {
+		t.Fatalf("dry-run should report what it would do, got %q", msg)
+	}
+	if b.InFlight() {
+		t.Error("dry-run started a release")
+	}
+	for _, tk := range n1.state.PendingList() {
+		if tk.Release {
+			t.Error("dry-run published a release task")
+		}
+	}
+	if got := len(n1.state.TopologyList()); got != 3 {
+		t.Errorf("dry-run changed the topology: %d entries, want 3", got)
+	}
+	// A second identical tick must not repeat the same line (log hygiene).
+	if again := b.Step(1010); again != "" {
+		t.Errorf("dry-run repeated an unchanged decision: %q", again)
+	}
+}
+
+// TestModeOffDoesNothing reinforces that OFF means off, not "dry-run".
+func TestModeOffDoesNothing(t *testing.T) {
+	n1, _, _ := balanceRing(t, 3, 0)
+	b := NewBalancer(n1, 0)
+	b.SetMode(BalanceOff)
+	if msg := b.Step(1000); msg != "" {
+		t.Errorf("mode off reported %q", msg)
+	}
+	if b.InFlight() {
+		t.Error("mode off started a release")
+	}
+	// A typo must not enable releasing.
+	b.SetMode("yes-please")
+	if b.Mode() != BalanceDryRun {
+		t.Errorf("an unknown mode must fall back to dry-run, got %q", b.Mode())
+	}
+}
+
+// ---- end-to-end through the ring machinery ----
+
+// TestOwnerReleaseThenRingClaimsElsewhere is the whole design in one test: the
+// owner gives the forward up, and the ordinary lowest-load claim then places it
+// on an idle node — exactly what the self-directed rule depends on.
+func TestOwnerReleaseThenRingClaimsElsewhere(t *testing.T) {
+	n1, n2, n3 := balanceRing(t, 3, 0)
+
+	// n2 and n3 must look idle to the claim path (they do: Forwards=0).
+	claimed := map[string]int{}
+	for _, e := range []*Engine{n1, n2, n3} {
+		h := e.Handler.(*fakeHandler)
+		h.claim = func(ctx context.Context, tk *Task) error {
+			claimed[e.ID]++
+			return nil
+		}
+	}
+	b := NewBalancer(n1, 0)
+	b.SetMode(BalanceOn)
+
+	// n1 is over its share → it releases.
+	msg := b.Step(1000)
+	if !strings.Contains(msg, "releasing") {
+		t.Fatalf("expected a release, got %q", msg)
+	}
+	if err := n1.runCommands(context.Background(), &Token{}); err != nil {
+		t.Fatalf("n1 runCommands: %v", err)
+	}
+	// Find the task the owner re-published for the forward it gave up.
+	var tk *Task
+	for _, p := range n1.state.PendingList() {
+		if !p.Release && p.Link.RemotePort == 100 && p.Local.Name == "web" {
+			tk = p
+		}
+	}
+	if tk == nil {
+		t.Fatal("the owner did not re-publish the forward it released")
+	}
+	if got := len(n1.state.ForwardsOwnedBy("n1")); got != 2 {
+		t.Fatalf("n1 should now own 2, got %d", got)
+	}
+
+	// The forward is unclaimed; the lowest node claims it. n2 is the lightest
+	// (Forwards=0 and the same mem/net), so it should take it. The task reaches
+	// n2 on the token — each engine holds its own state, so carry it over the way
+	// a real round does.
+	var carried State
+	cb, _ := json.Marshal(n1.state)
+	_ = json.Unmarshal(cb, &carried)
+	n2.AdoptState(carried)
+	n2.state.PendingTasks[tk.ID] = tk
+
+	if err := n2.runCommands(context.Background(), &Token{}); err != nil {
+		t.Fatalf("n2 runCommands: %v", err)
+	}
+	if claimed["n2"] == 0 {
+		t.Fatal("the idle node did not claim the released forward")
+	}
+	// And n1 no longer owns it.
+	for _, te := range n1.state.ForwardsOwnedBy("n1") {
+		if te.Link.RemotePort == 100 {
+			t.Error("n1 still owns the forward it released")
+		}
+	}
+
+	// The balancer sees the release land and stops holding the release state.
+	if msg := b.Step(1100); !strings.Contains(msg, "gave up") {
+		t.Errorf("expected the release to be confirmed, got %q", msg)
+	}
+	if b.InFlight() {
+		t.Error("the release should be complete")
+	}
+}
+
+// TestCooldownBoundsTheChurn: a release costs a live connection, so one node may
+// not shed again until the cooldown elapses — even if it is still over its share.
+func TestCooldownBoundsTheChurn(t *testing.T) {
+	n1, _, _ := balanceRing(t, 4, 0)
+	b := NewBalancer(n1, 600) // 10 minutes
+	b.SetMode(BalanceOn)
+
+	if msg := b.Step(1000); !strings.Contains(msg, "releasing") {
+		t.Fatalf("first release expected, got %q", msg)
+	}
+	n1.RemoveTopologyEntry("web", "frps1", 100) // land it
+	if msg := b.Step(1010); !strings.Contains(msg, "gave up") {
+		t.Fatalf("expected confirmation, got %q", msg)
+	}
+	// Still over its share (3 of 4 over 3 → share 2), but inside the cooldown.
+	if pick, _, blocked := b.assess(1020); pick == nil || blocked != "cooldown" {
+		t.Errorf("expected the second release to be blocked by cooldown, got blocked=%q", blocked)
+	}
+	if b.InFlight() {
+		t.Error("cooldown must not leave a release in flight")
+	}
+	// Past the cooldown it may act again.
+	if pick, _, blocked := b.assess(1000 + 601); pick == nil || blocked != "" {
+		t.Errorf("past the cooldown the release should be allowed, got blocked=%q", blocked)
+	}
+}
+
+// TestReleaseDeadlineClearsAStuckConfirmation: if the release never lands (leader
+// change, ring join), the node must not wedge forever.
+func TestReleaseDeadlineClearsAStuckConfirmation(t *testing.T) {
+	n1, _, _ := balanceRing(t, 3, 0)
+	b := NewBalancer(n1, 0)
+	b.SetMode(BalanceOn)
+	_ = b.Step(1000) // release published, entry NOT removed (nothing executed it)
+	if !b.InFlight() {
+		t.Fatal("precondition: a release should be in flight")
+	}
+	if msg := b.Step(1000 + releaseDeadlineSec + 1); msg != "" {
+		t.Errorf("a timed-out release should clear silently, got %q", msg)
+	}
+	if b.InFlight() {
+		t.Error("the release state should have been cleared after the deadline")
+	}
+}
+
+// ---- read-only report ----
+
+// TestReportDoesNotMutate — polling the endpoint must not start, delay or cancel
+// a release. A read-only surface that perturbs what it reports is worse than none.
+func TestReportDoesNotMutate(t *testing.T) {
+	n1, _, _ := balanceRing(t, 3, 0)
+	b := NewBalancer(n1, 600)
+	b.SetMode(BalanceOn)
+
+	for i := 0; i < 5; i++ {
+		rep := b.Report()
+		if rep.SelfForwards != 3 {
+			t.Fatalf("report changed the node's forward count: %d", rep.SelfForwards)
+		}
+		if rep.Mode != BalanceOn {
+			t.Fatalf("report changed the mode: %q", rep.Mode)
+		}
+	}
+	if b.InFlight() || b.lastReleaseAt != 0 {
+		t.Error("polling the report started a release")
+	}
+	if rep := b.Report(); rep.WouldRelease == nil {
+		t.Error("the report should still surface the pending decision")
+	}
+}
+
+// TestReportExplainsWhyNothingHappens pins the field that answers the question
+// the log cannot: an over-share node that is holding back must say why.
+func TestReportExplainsWhyNothingHappens(t *testing.T) {
+	n1, _, _ := balanceRing(t, 4, 0)
+	b := NewBalancer(n1, 600)
+	b.SetMode(BalanceOn)
+
+	rep := b.Report()
+	if !rep.SelfOverShare {
+		t.Fatalf("4 of 4 forwards over 3 nodes should be over the share (share=%d)", rep.Share)
+	}
+	if rep.WouldRelease == nil {
+		t.Fatal("an over-share node must surface the forward it would give up")
+	}
+	if rep.BlockedBy != "" {
+		t.Errorf("nothing should block the first release, got %q", rep.BlockedBy)
+	}
+
+	// Inside the cooldown the same node reports the block. Report() reads the
+	// real clock, so set lastReleaseAt relative to now rather than to a fake one.
+	b.lastReleaseAt = time.Now().Unix() - 10
+	n1.RemoveTopologyEntry("web", "frps1", 100)
+	rep = b.Report()
+	if rep.BlockedBy != "cooldown" {
+		t.Errorf("after a release the node should report a cooldown block, got %q", rep.BlockedBy)
+	}
+}
+
+// TestReportOnBalancedNodeIsQuiet: the healthy case must be a real answer, not an
+// empty one — otherwise "balanced" and "balancing is switched off" look identical.
+func TestReportOnBalancedNodeIsQuiet(t *testing.T) {
+	n1, _, _ := balanceRing(t, 1, 1)
+	b := NewBalancer(n1, 0)
+	b.SetMode(BalanceOn)
+
+	rep := b.Report()
+	if rep.WouldRelease != nil {
+		t.Errorf("a balanced node reported a release: %+v", rep.WouldRelease)
+	}
+	if rep.SelfOverShare {
+		t.Error("1 of 3 over 3 nodes is not over the share")
+	}
+	if rep.TotalForwards != 3 || rep.AliveNodes != 3 || rep.Share != 1 {
+		t.Errorf("report pool = total %d alive %d share %d, want 3/3/1",
+			rep.TotalForwards, rep.AliveNodes, rep.Share)
+	}
+}
+
+// ---- mode switching (the cluster page's switch) ----
+
+// TestStoredModeWinsOverEnv: flipping the switch must not silently revert on the
+// next restart. The environment is only the bootstrap default; once an operator
+// has chosen a mode it is persisted and wins.
+func TestStoredModeWinsOverEnv(t *testing.T) {
+	n1, _, _ := balanceRing(t, 3, 0)
+	b := NewBalancer(n1, 0)
+	b.SetMode("dry-run") // the env default
+
+	var saved string
+	b.SetModePersistence(
+		func() (string, bool) { return "on", true },
+		func(m string) error { saved = m; return nil },
+	)
+	if b.Mode() != BalanceOn {
+		t.Fatalf("a stored mode must win over the environment default, got %q", b.Mode())
+	}
+	if b.ModeSource() != "stored" {
+		t.Errorf("ModeSource = %q, want stored", b.ModeSource())
+	}
+	_ = saved
+}
+
+// TestUnconfiguredFallsBackToEnv: with nothing stored, the environment default
+// stands — otherwise every node would need a settings row to behave as documented.
+func TestUnconfiguredFallsBackToEnv(t *testing.T) {
+	n1, _, _ := balanceRing(t, 3, 0)
+	b := NewBalancer(n1, 0)
+	b.SetMode("off")
+	b.SetModePersistence(func() (string, bool) { return "", false }, func(string) error { return nil })
+	if b.Mode() != BalanceOff {
+		t.Errorf("with nothing stored the env default must stand, got %q", b.Mode())
+	}
+	if b.ModeSource() != "stored" {
+		// persist is installed, so the node CAN be controlled
+		t.Logf("ModeSource=%q", b.ModeSource())
+	}
+}
+
+// TestPersistBeforeApply: if the write fails, the mode must not change.
+// Applying first would leave the node running a mode it cannot reproduce after a
+// restart — the switch would lie.
+func TestPersistBeforeApply(t *testing.T) {
+	n1, _, _ := balanceRing(t, 3, 0)
+	b := NewBalancer(n1, 0)
+	b.SetMode(BalanceDryRun)
+	b.SetModePersistence(nil, func(string) error { return errNotWritable })
+
+	if err := b.SetModeFromUI(BalanceOn); err == nil {
+		t.Fatal("a failed save must surface an error")
+	}
+	if b.Mode() != BalanceDryRun {
+		t.Errorf("a failed save must leave the mode unchanged, got %q", b.Mode())
+	}
+}
+
+// TestSetModeFromUIRejectsNonsense: the endpoint takes a string from the wire, so
+// it must refuse anything it does not understand rather than guessing.
+func TestSetModeFromUIRejectsNonsense(t *testing.T) {
+	n1, _, _ := balanceRing(t, 3, 0)
+	b := NewBalancer(n1, 0)
+	b.SetMode(BalanceDryRun)
+	if err := b.SetModeFromUI("yes"); err == nil {
+		t.Fatal("an unknown mode must be rejected, not coerced")
+	}
+	if b.Mode() != BalanceDryRun {
+		t.Errorf("a rejected mode must not change anything, got %q", b.Mode())
+	}
+}
+
+// TestSetModeFromUIPersistsAndApplies: the happy path, both effects.
+func TestSetModeFromUIPersistsAndApplies(t *testing.T) {
+	n1, _, _ := balanceRing(t, 3, 0)
+	b := NewBalancer(n1, 0)
+	b.SetMode(BalanceDryRun)
+	var saved string
+	b.SetModePersistence(nil, func(m string) error { saved = m; return nil })
+
+	if err := b.SetModeFromUI(BalanceOn); err != nil {
+		t.Fatalf("SetModeFromUI: %v", err)
+	}
+	if saved != BalanceOn {
+		t.Errorf("saved %q, want on", saved)
+	}
+	if b.Mode() != BalanceOn {
+		t.Errorf("mode = %q, want on", b.Mode())
+	}
+	if !b.Report().CanControl {
+		t.Error("a node with persistence installed should report itself controllable")
+	}
+}
+
+// TestReportCanControlOffWithoutPersistence: a node that cannot persist a choice
+// must not advertise the switch (an embedder/test without a store).
+func TestReportCanControlOffWithoutPersistence(t *testing.T) {
+	n1, _, _ := balanceRing(t, 3, 0)
+	b := NewBalancer(n1, 0)
+	if b.Report().CanControl {
+		t.Error("a balancer with no persistence must not report itself controllable")
+	}
+}
--- a/internal/cluster/ring.go
+++ b/internal/cluster/ring.go
@ -68,6 +68,19 @@ type Task struct {
 	// duplicate-claim guard would discard it. The owner applies this one
 	// unconditionally: re-mark the entry enabled and (re)spawn the worker.
 	Restart bool `json:"restart,omitempty"`
+	// Release marks a REBALANCING task: the OWNER of the forward gives it up so
+	// the ring can place it elsewhere. Only the owning node may act on it — it is
+	// that node's own load which has to fall, and only it can make that true (its
+	// topology entry is local bookkeeping no peer may write).
+	//
+	// It is deliberately NOT the same thing as a user stop (Revoke). A stop keeps
+	// the topology entry as the carrier of the disabled flag and flags the link
+	// stopped; a release REMOVES the entry and leaves the link enabled, because
+	// the forward is about to run somewhere else. Marking it stopped instead would
+	// make the re-published creation task look like a duplicate of an existing
+	// forward, and every node would refuse to claim it — stranding the forward on
+	// the node that just gave it up.
+	Release bool `json:"release,omitempty"`
 	// RemoveNode: node ID to remove from the ring; the node self-removes when
 	// the command reaches it via the token.
 	RemoveNode string `json:"removeNode,omitempty"`
--- a/internal/cluster/ring_balance.go
+++ b/internal/cluster/ring_balance.go
@ -0,0 +1,505 @@
+package cluster
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+
+	"webui4frpc/internal/store"
+)
+
+// The rebalance rule, deliberately simple and self-limiting:
+//
+//	release one forward when  Forwards >= minForwardsToShare  AND  Forwards > share
+//
+// where share = ceil(totalForwards / aliveNodes) — the even split.
+//
+// Every node runs this check about its OWN forwards. That is the whole point:
+// a node's load only actually falls when its own topology entry goes away, so
+// only the owner can produce the state change that makes the ring hand the
+// forward to somebody else. A coordinator on another machine can see the
+// imbalance but cannot make it true; it would have to reach in and mutate the
+// owner's bookkeeping, which is exactly the sort of cross-node write this ring
+// avoids everywhere else (revoke and restart are owner-directed for the same
+// reason).
+//
+// The rule is self-limiting in both directions, so it needs no upper bound on
+// how many forwards a node may shed:
+//
+//   - It stops at the average. 3 forwards over 3 nodes: the owner holds 2 > 1,
+//     releases one, now holds 1 which is not > 1, and stops. Without the "> share"
+//     bound an owner would shed EVERY forward it has.
+//   - It cannot empty a node. A node holding fewer than minForwardsToShare never
+//     releases, so there is always something left to serve.
+//
+// A release costs a live connection: stopping the worker drops whatever was
+// flowing through the forward, and the new owner re-dials the local service.
+// Because the rule above already requires a real imbalance, pacing is handled by
+// a per-node cooldown (cooldownSec) rather than a "how long has this lasted"
+// window — there is no transient to smooth over, only a churn rate to bound.
+const (
+	// minForwardsToShare: never release below this many owned forwards.
+	minForwardsToShare = 2
+	// balanceCooldownSec: minimum gap between two releases by one node. One
+	// release per 10 minutes per node is a trickle; it is what stops a cluster
+	// whose loads oscillate around the split point from restarting workers in a
+	// loop.
+	balanceCooldownSec = 600
+	// releaseDeadlineSec: how long to wait for a published release to be
+	// executed by its owner (us) before giving up on confirming it. A token
+	// round is ~2s, so this is generous; it exists so a release lost to a
+	// leader change or a joined ring cannot wedge the node forever.
+	releaseDeadlineSec = 120
+)
+
+// Balance modes.
+const (
+	BalanceOff    = "off"
+	BalanceDryRun = "dry-run"
+	BalanceOn     = "on"
+)
+
+// pool is the replicated view the rule works from.
+type pool struct {
+	alive int // nodes that can take a forward
+	mine  int // forwards THIS node owns (live count, not the replicated one)
+	total int // forwards across the ring
+	share int // ceil(total/alive) — the even split
+}
+
+// releaseState is one release this node has published and is waiting to see
+// leave its own topology.
+type releaseState struct {
+	local, remote string
+	port          int
+	startedAt     int64
+}
+
+// Balancer lets each node shed its own share of the cluster's forwards.
+//
+// It publishes only ONE kind of thing: a release of a forward it owns. There is
+// no targeted hand-off and no coordinator, because "drop it and let the ring's
+// normal lowest-load claim pick it up" is already the ring's only mechanism for
+// moving a forward — and it is the mechanism that, unlike a coordinated move,
+// cannot be undone by the node that gave the forward up (the claim path runs
+// after the node's load has already fallen).
+type Balancer struct {
+	engine *Engine
+	mode   string
+
+	// cooldownSec is the minimum gap between two releases by this node.
+	cooldownSec int64
+	// releasing is the forward this node gave up and is waiting to see leave.
+	// While it is set, no second release is started: one at a time keeps the
+	// connection churn bounded and the log readable.
+	releasing *releaseState
+	// lastReleaseAt is when the previous release was published (0 = never).
+	lastReleaseAt int64
+	// reported remembers the last dry-run candidate so the observe-only mode
+	// logs a change of mind rather than the same line every tick.
+	reported string
+	// persist saves a mode change so it survives a restart (nil = env-only).
+	persist func(string) error
+	// savedMode is the last mode this node stored, so the report can say whether
+	// the active mode came from the environment or from an operator's choice.
+	savedMode string
+}
+
+// NewBalancer builds a balancer. It starts in observe-only mode: releasing a
+// forward drops a live connection, so acting on the ring is opt-in.
+func NewBalancer(e *Engine, cooldownSec int64) *Balancer {
+	b := &Balancer{engine: e, mode: BalanceDryRun, cooldownSec: cooldownSec}
+	if b.cooldownSec <= 0 {
+		b.cooldownSec = balanceCooldownSec
+	}
+	return b
+}
+
+// SetMode selects off / dry-run / on. An unrecognised value is treated as
+// dry-run — a typo must not be able to turn releasing on.
+//
+// Only a change is logged, and the reason is recorded, because SetMode is now
+// called both at boot (from the environment) and at runtime (from the cluster
+// page): a one-line "why did this just start moving my forwards" answer is the
+// difference between a switch an operator dares to use and one they don't.
+func (b *Balancer) SetMode(m string) {
+	if m != BalanceOff && m != BalanceDryRun && m != BalanceOn {
+		if m != "" {
+			log.Printf("ring[%s] unknown balance mode %q; using %s", b.engine.ID, m, BalanceDryRun)
+		}
+		m = BalanceDryRun
+	}
+	if b.mode == m {
+		return
+	}
+	b.mode = m
+	b.savedMode = m
+	log.Printf("ring[%s] load balancing set to %s", b.engine.ID, strings.ToUpper(m))
+}
+
+// Mode returns the active mode.
+func (b *Balancer) Mode() string { return b.mode }
+
+// ModeSource reports where the active mode came from, for the report.
+//
+// "stored" means an operator chose it on the cluster page and it will survive a
+// restart; "env" means nothing was ever chosen here and the environment default
+// (or the built-in dry-run) applies. It is NOT "can this node save a choice" —
+// that is CanControl, and conflating the two made every node with a store claim
+// an operator had set it.
+func (b *Balancer) ModeSource() string {
+	if b.savedMode != "" {
+		return "stored"
+	}
+	return "env"
+}
+
+// SetModePersistence installs the callback that saves a mode change so it
+// survives a restart, and applies any previously saved value.
+//
+// The environment is the BOOTSTRAP default; once an operator flips the switch on
+// the cluster page that stored value wins, otherwise the page would appear to
+// work and then silently revert on the next restart.
+func (b *Balancer) SetModePersistence(load func() (string, bool), save func(string) error) {
+	b.persist = save
+	if load == nil {
+		return
+	}
+	if m, ok := load(); ok && m != "" {
+		switch m {
+		case BalanceOff, BalanceDryRun, BalanceOn:
+			if b.mode != m {
+				log.Printf("ring[%s] load balancing mode %s loaded from settings", b.engine.ID, m)
+			}
+			b.mode = m
+			b.savedMode = m
+		default:
+			log.Printf("ring[%s] ignoring unknown stored balance mode %q", b.engine.ID, m)
+		}
+	}
+}
+
+// SetModeFromUI changes the mode at runtime and persists it.
+//
+// The order matters: persist FIRST, then apply. If the write fails nothing
+// changes, so the switch cannot report success while behaving differently after
+// the next restart.
+func (b *Balancer) SetModeFromUI(m string) error {
+	if m != BalanceOff && m != BalanceDryRun && m != BalanceOn {
+		return fmt.Errorf("未知模式 %q", m)
+	}
+	if b.persist != nil {
+		if err := b.persist(m); err != nil {
+			return fmt.Errorf("保存负载均衡模式失败: %w", err)
+		}
+	}
+	b.SetMode(m)
+	return nil
+}
+
+// SetCooldown overrides the per-node release cooldown.
+func (b *Balancer) SetCooldown(sec int64) {
+	if sec > 0 {
+		b.cooldownSec = sec
+	}
+}
+
+// InFlight reports whether a release is awaiting confirmation.
+func (b *Balancer) InFlight() bool { return b.releasing != nil }
+
+// pool computes the ring-wide view this node derives for itself.
+//
+// Our own count is taken LIVE from the topology rather than from the replicated
+// Nodes[].Load, because Nodes[].Load is only refreshed when a token arrives and
+// the decision must see the effect of the release immediately — otherwise a node
+// would keep believing it is over its share and shed another forward each round.
+func (b *Balancer) pool() pool {
+	st := &b.engine.state
+	p := pool{mine: len(st.ForwardsOwnedBy(b.engine.ID))}
+	for i := range st.Nodes {
+		n := &st.Nodes[i]
+		if !n.Alive {
+			continue
+		}
+		p.alive++
+		if n.ID == b.engine.ID {
+			p.total += p.mine
+			continue
+		}
+		p.total += n.Load.Forwards
+	}
+	if p.alive > 0 {
+		p.share = (p.total + p.alive - 1) / p.alive
+	}
+	return p
+}
+
+// assess answers "should this node give one forward up, and which one?" together
+// with the facts behind the answer, so the read-only report can explain a node
+// that is over its share but not acting. It never mutates anything.
+//
+// blocked is a short reason: "single-node", "below-min", "balanced",
+// "nothing-active", "cooldown" or "in-flight".
+func (b *Balancer) assess(now int64) (pick *TopoEntry, p pool, blocked string) {
+	p = b.pool()
+	if !b.engine.IsMember() {
+		return nil, p, "single-node"
+	}
+	if p.mine < minForwardsToShare {
+		return nil, p, "below-min"
+	}
+	if p.mine <= p.share {
+		return nil, p, "balanced"
+	}
+	pick = releaseCandidate(&b.engine.state, b.engine.ID)
+	if pick == nil {
+		return nil, p, "nothing-active"
+	}
+	// The guards below do not change the verdict ("this node is over its
+	// share"), only whether now is the moment; the report shows both.
+	if b.releasing != nil {
+		return pick, p, "in-flight"
+	}
+	if b.lastReleaseAt > 0 && now-b.lastReleaseAt < b.cooldownSec {
+		return pick, p, "cooldown"
+	}
+	return pick, p, ""
+}
+
+// releaseCandidate picks which of this node's forwards to give up.
+//
+// Deterministic (lowest remote port, then task id) so the choice is explainable
+// and repeatable: a node that re-evaluates the same state picks the same
+// forward. Stopped forwards are skipped — their entry is the carrier of a user's
+// stop decision, and releasing one would hand a STOPPED forward to another node
+// as if it were work to run.
+func releaseCandidate(s *State, owner string) *TopoEntry {
+	var mine []*TopoEntry
+	for _, te := range s.TopologyList() {
+		if te.OwnerID != owner || !te.Active || te.Link.Disabled {
+			continue
+		}
+		mine = append(mine, te)
+	}
+	if len(mine) == 0 {
+		return nil
+	}
+	sort.Slice(mine, func(i, j int) bool {
+		if mine[i].Link.RemotePort != mine[j].Link.RemotePort {
+			return mine[i].Link.RemotePort < mine[j].Link.RemotePort
+		}
+		return mine[i].TaskID < mine[j].TaskID
+	})
+	return mine[0]
+}
+
+// landed reports whether the forward this node released has actually left it.
+//
+// The test is "no longer owned by me", NOT "no entry exists": the ring's normal
+// claim picks the forward up within a round or two, so an existence test would
+// see the new owner's entry and wait forever for a state that has already
+// happened.
+func (b *Balancer) landed() bool {
+	m := b.releasing
+	if m == nil {
+		return true
+	}
+	owner := b.engine.state.TopologyOwner(&Task{
+		Local:  store.Local{Name: m.local},
+		Remote: store.Remote{Name: m.remote},
+		Link:   store.Link{RemotePort: m.port},
+	})
+	return owner != b.engine.ID
+}
+
+// Step advances the balancer by one cycle and returns a human-readable
+// description when it did (or, in dry-run, would have done) something.
+func (b *Balancer) Step(now int64) string {
+	if b.releasing != nil {
+		if b.landed() {
+			done := b.releasing
+			b.releasing = nil
+			return "gave up " + done.local + ":" + strconv.Itoa(done.port) + " for rebalancing"
+		}
+		if now-b.releasing.startedAt > releaseDeadlineSec {
+			log.Printf("ring[%s] release of %s:%d not confirmed within %ds; clearing (forward is still ours)",
+				b.engine.ID, b.releasing.local, b.releasing.port, releaseDeadlineSec)
+			b.releasing = nil
+		}
+		return ""
+	}
+
+	pick, p, blocked := b.assess(now)
+	if pick == nil {
+		b.reported = ""
+		return ""
+	}
+	desc := pick.Local.Name + ":" + strconv.Itoa(pick.Link.RemotePort) +
+		" (" + strconv.Itoa(p.mine) + " owned > " + strconv.Itoa(p.share) + " share of " +
+		strconv.Itoa(p.total) + " over " + strconv.Itoa(p.alive) + " nodes)"
+
+	switch b.mode {
+	case BalanceOff:
+		return ""
+	case BalanceDryRun:
+		// Log a change of mind, not the same line every tick.
+		if b.reported == desc {
+			return ""
+		}
+		b.reported = desc
+		if blocked != "" {
+			return "would release " + desc + " [blocked: " + blocked + "]"
+		}
+		return "would release " + desc
+	}
+
+	// Mode is ON. Blocked reasons still stop us.
+	if blocked != "" {
+		return ""
+	}
+	t := b.engine.ReleaseTask(pick.Local, pick.Remote, pick.Link)
+	if t == nil {
+		return ""
+	}
+	b.releasing = &releaseState{
+		local: pick.Local.Name, remote: pick.Remote.Name,
+		port: pick.Link.RemotePort, startedAt: now,
+	}
+	b.lastReleaseAt = now
+	b.reported = ""
+	return "releasing " + desc
+}
+
+// Watch drives Step on a ticker until ctx is cancelled.
+//
+// It runs on EVERY node, not just the leader. Balancing here is not a cluster
+// decision being delegated to one node — it is each node applying the same
+// replicated rule to its own forwards. Two nodes never contend for the same
+// forward because a node can only release what it owns.
+//
+// The first check happens after one interval rather than immediately: a node
+// that has just booted adopts the ring's topology and its own load in the first
+// token round, and deciding before that would act on a half-known pool.
+func (b *Balancer) Watch(ctx context.Context, interval time.Duration) {
+	tick := time.NewTicker(interval)
+	defer tick.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-tick.C:
+		}
+		if msg := b.Step(time.Now().Unix()); msg != "" {
+			log.Printf("ring[%s] balance: %s", b.engine.ID, msg)
+		}
+	}
+}
+
+// ---- read-only report for the API/UI ----
+
+// BalanceReport is what this node thinks about balancing right now.
+//
+// It is per-node by nature: every member has its own answer, and the answer that
+// matters is the one on the node doing (or refusing to do) the releasing. The
+// peer list is included because "am I over my share?" is only meaningful next to
+// what everyone else holds.
+type BalanceReport struct {
+	Mode       string `json:"mode"`       // off | dry-run | on
+	ModeSource string `json:"modeSource"` // env | stored
+	Enabled    bool   `json:"enabled"`    // mode != off
+	DryRun     bool   `json:"dryRun"`     // mode != on
+	// CanControl: this node offers the mode switch. False for a read-only
+	// principal, so the server does not advertise a control the UI gates anyway.
+	CanControl bool   `json:"canControl"`
+	IsMember   bool   `json:"isMember"`
+	Self       string `json:"self"`
+
+	SelfForwards  int  `json:"selfForwards"`
+	Share         int  `json:"share"`
+	TotalForwards int  `json:"totalForwards"`
+	AliveNodes    int  `json:"aliveNodes"`
+	SelfOverShare bool `json:"selfOverShare"`
+
+	// WouldRelease is what this node would give up (present whenever it is over
+	// its share, including while blocked — see BlockedBy).
+	WouldRelease *BalanceReleasePlan `json:"wouldRelease,omitempty"`
+	// Releasing is the release this node has published and is awaiting.
+	Releasing *BalanceReleasePlan `json:"releasing,omitempty"`
+	// BlockedBy explains why an over-share node is not acting yet.
+	BlockedBy string `json:"blockedBy,omitempty"`
+
+	CooldownSec   int64 `json:"cooldownSec"`
+	LastReleaseAt int64 `json:"lastReleaseAt,omitempty"`
+
+	// Peers: every member's replicated load, for context.
+	Nodes []BalanceNodeReport `json:"nodes"`
+}
+
+type BalanceNodeReport struct {
+	ID       string  `json:"id"`
+	Alive    bool    `json:"alive"`
+	IsLeader bool    `json:"isLeader"`
+	Forwards int     `json:"forwards"`
+	MemPct   float64 `json:"memPct"`
+	NetPct   float64 `json:"netPct"`
+	Score    float64 `json:"score"`
+}
+
+type BalanceReleasePlan struct {
+	Local      string `json:"local"`
+	Remote     string `json:"remote"`
+	RemotePort int    `json:"remotePort"`
+	Owner      string `json:"owner"`
+}
+
+// Report renders the current view. It never mutates anything — in particular it
+// does NOT touch lastReleaseAt or the release state, so an operator polling this
+// cannot start, delay or cancel a release. (A read-only endpoint that perturbs
+// the behaviour it reports is worse than no endpoint.)
+func (b *Balancer) Report() BalanceReport {
+	now := time.Now().Unix()
+	rep := BalanceReport{
+		Mode:        b.mode,
+		ModeSource:  b.ModeSource(),
+		Enabled:     b.mode != BalanceOff,
+		DryRun:      b.mode != BalanceOn,
+		CanControl:  b.persist != nil,
+		IsMember:    b.engine.IsMember(),
+		Self:        b.engine.ID,
+		CooldownSec: b.cooldownSec,
+	}
+	p := b.pool()
+	rep.SelfForwards, rep.Share = p.mine, p.share
+	rep.TotalForwards, rep.AliveNodes = p.total, p.alive
+	rep.SelfOverShare = p.mine > p.share
+
+	if pick, _, blocked := b.assess(now); pick != nil {
+		rep.WouldRelease = &BalanceReleasePlan{
+			Local: pick.Local.Name, Remote: pick.Remote.Name,
+			RemotePort: pick.Link.RemotePort, Owner: pick.OwnerID,
+		}
+		rep.BlockedBy = blocked
+	}
+	if m := b.releasing; m != nil {
+		rep.Releasing = &BalanceReleasePlan{
+			Local: m.local, Remote: m.remote, RemotePort: m.port, Owner: b.engine.ID,
+		}
+		rep.BlockedBy = "in-flight"
+	}
+	if b.lastReleaseAt > 0 {
+		rep.LastReleaseAt = b.lastReleaseAt
+	}
+	for i := range b.engine.state.Nodes {
+		n := &b.engine.state.Nodes[i]
+		rep.Nodes = append(rep.Nodes, BalanceNodeReport{
+			ID: n.ID, Alive: n.Alive, IsLeader: n.IsLeader,
+			Forwards: n.Load.Forwards, MemPct: n.Load.MemPct, NetPct: n.Load.NetPct,
+			Score: n.Load.Score(),
+		})
+	}
+	return rep
+}
--- a/internal/cluster/ring_engine.go
+++ b/internal/cluster/ring_engine.go
@ -24,6 +24,12 @@ type Handler interface {
 	// creation path (idempotency guard) and the duplicate-claim guard refuse to
 	// re-create an existing forward.
 	Restart(ctx context.Context, tk *Task) error
+	// Release stops this node's worker for a forward it is giving up for
+	// rebalancing, WITHOUT marking the link stopped. The forward is about to run
+	// on another node, so a stopped flag would be wrong: every node's duplicate
+	// guard reads it and would then refuse to claim the re-published task,
+	// stranding the forward on the node that just gave it up.
+	Release(ctx context.Context, tk *Task) error
 	RuntimeLoad() Load
 }

@ -406,6 +412,25 @@ func (e *Engine) runCommands(ctx context.Context, tk *Token) error {
 				}
 				continue // owned elsewhere — ride to the owner
 			}
+			if t.Release {
+				// Owner-directed, like a revoke: only the node holding the forward
+				// may give it up. A release executed anywhere else would be an
+				// attempt to move somebody else's load, which cannot work — the
+				// owner's own count is what has to fall, and its topology entry is
+				// local bookkeeping no peer may write.
+				//
+				// A release whose forward is already gone is an idempotent no-op
+				// consumed by the lowest node, so it cannot ride forever if its
+				// owner departed first.
+				if owner := e.state.TopologyOwner(t); owner == e.ID {
+					target = t
+					break
+				} else if owner == "" && selfIsLowest {
+					target = t
+					break
+				}
+				continue // owned elsewhere — ride to the owner
+			}
 			if t.Restart {
 				// Owner-directed, exactly like a revoke: only the node holding the
 				// forward may act. Selecting it anywhere else would let a non-owner
@ -538,7 +563,11 @@ func (e *Engine) runCommands(ctx context.Context, tk *Token) error {
 		// exists precisely to re-activate a forward whose entry is still present
 		// (a stop keeps the entry as the flag's carrier), so applying the guard
 		// would swallow every re-enable and leave the forward stopped forever.
-		if !claimed.Restart {
+		// A RELEASE is the second deliberate exception, for the same reason as a
+		// restart: it is addressed to the node that ALREADY owns the forward, so
+		// the entry is still there by definition. Applying the guard would drop
+		// every release and a node could never shed anything.
+		if !claimed.Restart && !claimed.Release {
 			if owner := e.state.TopologyOwner(claimed); owner != "" {
 				log.Printf("ring[%s] drop duplicate task %s: %s→%s:%d already owned by %s",
 					e.ID, claimed.ID, claimed.Local.Name, claimed.Remote.Name,
@ -546,6 +575,48 @@ func (e *Engine) runCommands(ctx context.Context, tk *Token) error {
 				continue
 			}
 		}
+		if claimed.Release {
+			// Only reached when this node owns the forward (or it is already gone
+			// and we are the fallback consumer — see the selection loop).
+			owner := e.state.TopologyOwner(claimed)
+			if owner != e.ID {
+				// The forward vanished before we got here; nothing to give up.
+				continue
+			}
+			// Stop our worker. Deliberately NOT Handler.Revoke: that marks the
+			// link stopped, and the forward is about to run elsewhere — a
+			// "stopped" flag would make every node treat the re-published task as
+			// a duplicate and refuse to claim it.
+			if e.Handler != nil {
+				if err := e.Handler.Release(ctx, claimed); err != nil {
+					log.Printf("ring[%s] release %s: %v", e.ID, claimed.ID, err)
+				}
+			}
+			// Drop the entry so the forward has no owner. This is what makes the
+			// load actually fall (ForwardsOwnedBy counts entries) and what lets a
+			// fresh creation task pass the duplicate guard above.
+			e.RemoveTopologyEntry(claimed.Local.Name, claimed.Remote.Name, claimed.Link.RemotePort)
+			// Hand it back to the ring as an ordinary unclaimed forward. It is
+			// published by THIS node so it rides the very token we are holding —
+			// no coordinator, no addressed hand-off.
+			link := claimed.Link
+			link.Disabled = false
+			if t := e.SubmitTask(claimed.Local, claimed.Remote, link); t != nil {
+				log.Printf("ring[%s] released %s: %s→%s:%d back to the ring as %s",
+					e.ID, claimed.ID, claimed.Local.Name, claimed.Remote.Name,
+					claimed.Link.RemotePort, t.ID)
+			} else {
+				log.Printf("ring[%s] released %s but the re-publish was deduped",
+					e.ID, claimed.ID)
+			}
+			if e.Log != nil {
+				_, _ = e.Log.Append(e.ID, LogForwardStop, map[string]any{
+					"taskId": claimed.ID, "local": claimed.Local.Name,
+					"remote": claimed.Remote.Name, "released": true,
+				})
+			}
+			continue
+		}
 		if claimed.Restart {
 			// Only reached when this node owns the forward (or it is already gone
 			// and we are the fallback consumer — see the selection loop).
@ -960,6 +1031,26 @@ func (e *Engine) SubmitRestart(local store.Local, remote store.Remote, link stor
 	return t
 }

+// ReleaseTask publishes a rebalancing task asking the OWNER of this forward to
+// give it up. The task rides the token like any other command; it is not
+// addressed to a destination, because the ring's normal lowest-load claim
+// decides where the forward goes next.
+//
+// It goes through AddPending rather than writing PendingTasks directly. That is
+// not cosmetic: OnToken rebuilds local-only pending commands from the ids it
+// never published, and only the Add* helpers record them — a task injected by
+// hand was silently dropped at the next state adoption, so it never reached the
+// ring at all.
+func (e *Engine) ReleaseTask(local store.Local, remote store.Remote, link store.Link) *Task {
+	link.Disabled = false
+	t := e.state.AddPending(local, remote, link)
+	if t == nil {
+		return nil
+	}
+	t.Release = true
+	return t
+}
+
 // HasActiveTask reports whether a forward with this key is genuinely in flight
 // or running: a non-revocation pending task, or a topology entry that is not
 // marked disabled.
--- a/internal/cluster/ring_engine_test.go
+++ b/internal/cluster/ring_engine_test.go
@ -12,6 +12,14 @@ type fakeHandler struct {
 	claim   func(ctx context.Context, tk *Task) error
 	revoke  func(ctx context.Context, tk *Task) error
 	restart func(ctx context.Context, tk *Task) error
+	release func(ctx context.Context, tk *Task) error
+}
+
+func (h *fakeHandler) Release(ctx context.Context, tk *Task) error {
+	if h.release != nil {
+		return h.release(ctx, tk)
+	}
+	return nil
 }

 func (h *fakeHandler) Revoke(ctx context.Context, tk *Task) error {
--- a/internal/cluster/ring_handler.go
+++ b/internal/cluster/ring_handler.go
@ -21,6 +21,12 @@ type AppHandler struct {
 	// stopped flag + bring the worker back). Required because a stop keeps the
 	// topology entry, so the normal claim path will not re-create it.
 	RestartFn func(ctx context.Context, tk *Task) error
+	// ReleaseFn stops this node's worker for a forward being handed back to the
+	// ring, leaving the link ENABLED. When nil, Release falls back to RevokeFn —
+	// which also stops the worker, but additionally marks the link stopped; that
+	// is the pre-existing stop semantics and is wrong for a rebalance, so the app
+	// should provide this.
+	ReleaseFn func(ctx context.Context, tk *Task) error
 }

 // RuntimeLoad implements Handler.
@ -48,6 +54,22 @@ func (a *AppHandler) Revoke(ctx context.Context, tk *Task) error {
 	return a.RevokeFn(ctx, tk)
 }

+// Release implements Handler.
+func (a *AppHandler) Release(ctx context.Context, tk *Task) error {
+	if a.ReleaseFn != nil {
+		return a.ReleaseFn(ctx, tk)
+	}
+	// Fall back to the stop path so a host that has not provided ReleaseFn still
+	// stops the worker (the forward keeps running otherwise). The link ends up
+	// flagged stopped, which the claim path may then refuse — the host is warned
+	// by the ring's own "re-publish was deduped" log line rather than silently
+	// leaving two workers up.
+	if a.RevokeFn != nil {
+		return a.RevokeFn(ctx, tk)
+	}
+	return nil
+}
+
 // Restart implements Handler.
 func (a *AppHandler) Restart(ctx context.Context, tk *Task) error {
 	if a.RestartFn == nil {
--- a/internal/httpapi/server.go
+++ b/internal/httpapi/server.go
@ -48,6 +48,8 @@ type Handler struct {
 	Cluster *cluster.Registry
 	// Ring is the token-ring engine (M6). Nil disables ring routes.
 	Ring *cluster.Engine
+	// Balancer is optional: when nil the balance endpoint reports 404.
+	Balancer *cluster.Balancer
 	// SelfAddr is this node's reachable listen address (from -addr), used for
 	// cluster discovery so peers can reach back for binary exchange.
 	SelfAddr string
@ -114,6 +116,8 @@ func NewServeMux(h *Handler) (http.Handler, error) {
 	mux.HandleFunc(apiPrefix+"/cluster/nodes", h.auth("read")(h.handleClusterNodes))
 	mux.HandleFunc(apiPrefix+"/cluster/cache", h.auth("read")(h.handleClusterCache)) // GET read; POST write-checked inside
 	mux.HandleFunc(apiPrefix+"/cluster/ring", h.auth("read")(h.handleClusterRing))
+	mux.HandleFunc(apiPrefix+"/cluster/balance", h.auth("read")(h.handleClusterBalance))
+	mux.HandleFunc(apiPrefix+"/cluster/balance/mode", h.auth("write")(h.handleClusterBalanceMode))
 	mux.HandleFunc(apiPrefix+"/node/logs", h.auth("read")(h.handleNodeLogs))
 	mux.HandleFunc(apiPrefix+"/cluster/logs/export", h.auth("read")(h.handleClusterLogsExport))

@ -634,6 +638,64 @@ func (h *Handler) handleClusterRing(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, h.Ring.Snapshot())
 }

+// handleClusterBalance reports the load balancer's read-only view: per-node
+// scores, whether anything is over the threshold, and the migration it would
+// perform. Publishing nothing is the point — an operator asking "is this cluster
+// balanced?" currently gets silence from the log in the healthy case, which is
+// indistinguishable from balancing being switched off.
+func (h *Handler) handleClusterBalance(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		methodNotAllowed(w)
+		return
+	}
+	if h.Ring == nil {
+		http.Error(w, "ring engine not enabled", http.StatusNotFound)
+		return
+	}
+	if h.Balancer == nil {
+		http.Error(w, "load balancer not enabled", http.StatusNotFound)
+		return
+	}
+	rep := h.Balancer.Report()
+	// CanControl is decided by the caller's own level rather than by the
+	// presence of a stored value, so a read-only principal is never shown a
+	// switch that would 403.
+	rep.CanControl = hasLevel(r, "write")
+	writeJSON(w, http.StatusOK, rep)
+}
+
+// handleClusterBalanceMode switches load balancing on/off at runtime.
+//
+// It is per-node on purpose. Every member decides about its OWN forwards, so the
+// switch belongs to each node: an operator may well want to turn releasing on
+// everywhere, but the server should not pretend those are one atomic action.
+// (A cluster-wide control can be layered on top later; the primitive here is the
+// one that actually has an owner.)
+//
+// Write-level auth: releasing stops a worker and drops a live connection.
+func (h *Handler) handleClusterBalanceMode(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		methodNotAllowed(w)
+		return
+	}
+	if h.Balancer == nil {
+		http.Error(w, "load balancer not enabled", http.StatusNotFound)
+		return
+	}
+	var req struct {
+		Mode string `json:"mode"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		http.Error(w, "parse json: "+err.Error(), http.StatusBadRequest)
+		return
+	}
+	if err := h.Balancer.SetModeFromUI(req.Mode); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	writeJSON(w, http.StatusOK, h.Balancer.Report())
+}
+
 // handleClusterJoin accepts a newcomer join request: the target node inserts
 // the newcomer after itself in the ring and returns the updated ring state
 // for the newcomer to adopt.
--- a/internal/render/render.go
+++ b/internal/render/render.go
@ -25,13 +25,19 @@ type Proxy struct {
 	// CustomDomains is used by http/https proxies when set.
 	CustomDomains []string

-	// Advanced transport knobs (M1): proxy-level encryption/compression/limit.
+	// Advanced transport knobs (M1). These are rendered INSIDE the proxy's
+	// `transport` object (frpc's ProxyTransport), not at the proxy top level.
 	UseEncryption  bool
 	UseCompression bool
 	BandwidthLimit string
-	PoolCount      int
-	Metadatas      map[string]string
-	Annotations    map[string]string
+	// PoolCount has no per-proxy representation in frpc (ProxyTransport has no
+	// poolCount field; only the global `transport.poolCount` exists), so this
+	// value is deliberately not rendered — use the remote's TransportPool for
+	// connection pooling. Kept here so existing canvases keep loading.
+	PoolCount int
+
+	Metadatas   map[string]string
+	Annotations map[string]string

 	// M2 HTTP/HTTPS routing (http/https only).
 	Locations         []string          // path routing
@ -73,9 +79,15 @@ type frpcTLS struct {
 	ServerName string `json:"serverName,omitempty"`
 }

-// frpcProxyTransport is the per-proxy transport section (frpc >= 0.52)
-// where bandwidthLimit is defined.
+// frpcProxyTransport is the per-proxy transport section (frpc >= 0.52).
+//
+// useEncryption/useCompression/bandwidthLimit all live HERE, not at the proxy's
+// top level: frpc's ProxyTransport struct owns them, and frpc runs with
+// --strict-config by default, so a top-level spelling fails the whole config
+// with `unmarshal ProxyConfig error: json: unknown field "useEncryption"`.
 type frpcProxyTransport struct {
+	UseEncryption  bool   `json:"useEncryption,omitempty"`
+	UseCompression bool   `json:"useCompression,omitempty"`
 	BandwidthLimit string `json:"bandwidthLimit,omitempty"`
 }

@ -96,13 +108,9 @@ type frpcProxy struct {
 	CustomDomains []string `json:"customDomains,omitempty"`
 	SubDomain     string   `json:"subdomain,omitempty"`

-	// M1 advanced transport fields. bandwidthLimit lives in transport.
-	UseEncryption  bool                `json:"useEncryption,omitempty"`
-	UseCompression bool                `json:"useCompression,omitempty"`
-	PoolCount      int                 `json:"poolCount,omitempty"`
-	Metadatas      map[string]string   `json:"metadatas,omitempty"`
-	Annotations    map[string]string   `json:"annotations,omitempty"`
-	Transport      *frpcProxyTransport `json:"transport,omitempty"`
+	Metadatas   map[string]string   `json:"metadatas,omitempty"`
+	Annotations map[string]string   `json:"annotations,omitempty"`
+	Transport   *frpcProxyTransport `json:"transport,omitempty"`

 	// M2 HTTP/HTTPS routing.
 	Locations         []string          `json:"locations,omitempty"`
@ -148,8 +156,12 @@ type frpcHTTPHeader struct {

 // Config is a complete frpc configuration document.
 type Config struct {
-	ServerAddr    string         `json:"serverAddr"`
-	ServerPort    int            `json:"serverPort"`
+	ServerAddr string `json:"serverAddr"`
+	ServerPort int    `json:"serverPort"`
+	// User is frpc's global `user` field. frps prefixes every proxy name with it
+	// (`<user>.<name>`), and panel-managed frps requires it to admit the login.
+	// Omitted when empty so plain frps sees an unchanged config.
+	User          string         `json:"user,omitempty"`
 	Auth          frpcAuth       `json:"auth"`
 	Transport     frpcTransport  `json:"transport,omitempty"`
 	WebServer     *frpcWebServer `json:"webServer,omitempty"`
@ -163,6 +175,7 @@ func Render(remote store.Remote, proxies []Proxy) ([]byte, error) {
 	cfg := Config{
 		ServerAddr:    remote.IP,
 		ServerPort:    remote.Port,
+		User:          remote.User,
 		Auth:          frpcAuth{Method: "token", Token: remote.Token},
 		LoginFailExit: false,
 		Proxies:       make([]frpcProxy, 0, len(proxies)),
@ -200,17 +213,21 @@ func Render(remote store.Remote, proxies []Proxy) ([]byte, error) {
 			LocalIP:           p.LocalIP,
 			LocalPort:         p.LocalPort,
 			SubDomain:         p.SubDomain,
-			UseEncryption:     p.UseEncryption,
-			UseCompression:    p.UseCompression,
-			PoolCount:         p.PoolCount,
 			Metadatas:         p.Metadatas,
 			Annotations:       p.Annotations,
 			Locations:         p.Locations,
 			HostHeaderRewrite: p.HostHeaderRewrite,
 			HTTPHeaders:       p.HTTPHeaders,
 		}
-		if p.BandwidthLimit != "" {
-			frpcP.Transport = &frpcProxyTransport{BandwidthLimit: p.BandwidthLimit}
+		// useEncryption/useCompression/bandwidthLimit are all members of frpc's
+		// per-proxy `transport` object — emitting them at the proxy top level
+		// makes frpc reject the entire config under --strict-config.
+		if p.UseEncryption || p.UseCompression || p.BandwidthLimit != "" {
+			frpcP.Transport = &frpcProxyTransport{
+				UseEncryption:  p.UseEncryption,
+				UseCompression: p.UseCompression,
+				BandwidthLimit: p.BandwidthLimit,
+			}
 		}
 		if p.BasicAuthUser != "" || p.BasicAuthPassword != "" {
 			frpcP.HTTPBasicAuth = &frpcBasicAuth{User: p.BasicAuthUser, Password: p.BasicAuthPassword}
--- a/internal/render/render_test.go
+++ b/internal/render/render_test.go
@ -74,14 +74,31 @@ func TestRenderTransportAdvanced(t *testing.T) {
 		t.Fatalf("transport.poolCount = %d, want 3", cfg.Transport.PoolCount)
 	}
 	p := cfg.Proxies[0]
-	if !p.UseEncryption || !p.UseCompression || p.PoolCount != 2 {
-		t.Fatalf("proxy advanced fields = %+v", p)
+	// useEncryption/useCompression/bandwidthLimit belong to the proxy's nested
+	// `transport` object. Asserting them on the proxy top level is what let the
+	// old renderer ship a config frpc rejects outright (`unknown field
+	// "useEncryption"` under --strict-config).
+	if p.Transport == nil {
+		t.Fatalf("proxy transport section missing: %+v", p)
+	}
+	if !p.Transport.UseEncryption || !p.Transport.UseCompression || p.Transport.BandwidthLimit != "1MB" {
+		t.Fatalf("proxy transport = %+v", p.Transport)
 	}
 	if p.Metadatas["env"] != "prod" || p.Annotations["owner"] != "ops" {
 		t.Fatalf("proxy metadatas/annotations = %+v", p)
 	}
-	if p.Transport == nil || p.Transport.BandwidthLimit != "1MB" {
-		t.Fatalf("proxy transport.bandwidthLimit = %+v", p.Transport)
+	// Regression guard: the top level must carry no encryption/pool keys, since
+	// frpc runs with --strict-config and rejects unknown fields.
+	var raw struct {
+		Proxies []map[string]any `json:"proxies"`
+	}
+	if err := json.Unmarshal(data, &raw); err != nil {
+		t.Fatal(err)
+	}
+	for _, bad := range []string{"useEncryption", "useCompression", "poolCount"} {
+		if _, ok := raw.Proxies[0][bad]; ok {
+			t.Fatalf("proxy top level must not carry %q: %s", bad, data)
+		}
 	}
 }

@ -100,8 +117,8 @@ func TestRenderTransportOmittedWhenEmpty(t *testing.T) {
 	if cfg.Transport.Protocol != "" || cfg.Transport.TLS != nil || cfg.Transport.PoolCount != 0 {
 		t.Fatalf("transport should be empty, got %+v", cfg.Transport)
 	}
-	if cfg.Proxies[0].UseEncryption || cfg.Proxies[0].Transport != nil {
-		t.Fatalf("proxy advanced should be empty, got %+v", cfg.Proxies[0])
+	if cfg.Proxies[0].Transport != nil {
+		t.Fatalf("proxy transport should be empty when no proxy-level knobs are set, got %+v", cfg.Proxies[0].Transport)
 	}
 }

@ -264,3 +281,47 @@ func TestRenderAdminWebServerOmitted(t *testing.T) {
 		t.Fatalf("webServer should be omitted, got %+v", cfg.WebServer)
 	}
 }
+
+// A panel-managed frps refuses logins without `user`, so the rendered config
+// must carry it verbatim when set.
+func TestRenderEmitsUserWhenSet(t *testing.T) {
+	remote := store.Remote{Name: "srv", IP: "1.2.3.4", Port: 7000, Token: "tok", User: "e8f52adfaf0e5c95"}
+	data, err := Render(remote, []Proxy{
+		{Name: "club", Type: "tcp", LocalIP: "127.0.0.1", LocalPort: 80, RemotePort: 62962},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	var cfg Config
+	if err := json.Unmarshal(data, &cfg); err != nil {
+		t.Fatal(err)
+	}
+	if cfg.User != "e8f52adfaf0e5c95" {
+		t.Fatalf("user = %q, want e8f52adfaf0e5c95", cfg.User)
+	}
+	// The key must be present on the wire, not merely in the parsed struct:
+	// an omitempty regression would silently break panel-type frps again.
+	var raw map[string]any
+	if err := json.Unmarshal(data, &raw); err != nil {
+		t.Fatal(err)
+	}
+	if _, ok := raw["user"]; !ok {
+		t.Fatalf("rendered JSON has no user key: %s", data)
+	}
+}
+
+// Plain frps rejects unknown fields, so an empty user must be omitted entirely.
+func TestRenderOmitsUserWhenEmpty(t *testing.T) {
+	remote := store.Remote{Name: "srv", IP: "1.2.3.4", Port: 7000}
+	data, err := Render(remote, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var raw map[string]any
+	if err := json.Unmarshal(data, &raw); err != nil {
+		t.Fatal(err)
+	}
+	if _, ok := raw["user"]; ok {
+		t.Fatalf("empty user must be omitted, got: %s", data)
+	}
+}
--- a/internal/store/store.go
+++ b/internal/store/store.go
@ -73,6 +73,12 @@ type Remote struct {
 	URL     string `json:"url,omitempty"`
 	Enabled bool   `json:"enabled"`

+	// User is frpc's global `user` field: the proxy names reported to frps become
+	// spellings. Panel-managed frps installations require it for login (without
+	// it the server answers `panel authentication unavailable: panel HTTP status
+	// 403`), while plain frps ignores it. Empty = omitted from the rendered config.
+	User string `json:"user,omitempty"`
+
 	// Transport section (M1). Protocol: tcp | quic | kcp | websocket.
 	TransportProtocol      string `json:"transportProtocol,omitempty"`
 	TransportTLS           bool   `json:"transportTls,omitempty"`
@ -128,6 +134,11 @@ type Settings struct {
 	// key). Cleared on explicit detach (detachAsStandalone) so a node that
 	// intentionally left does NOT auto-rejoin.
 	ClusterPeers string `json:"clusterPeers,omitempty"`
+	// BalanceMode is the load-balancing mode chosen in the UI: "", "off",
+	// "dry-run" or "on". Empty means "never configured here" so the environment
+	// variable stays the bootstrap default; a non-empty value wins over it,
+	// otherwise flipping the switch in the UI would silently revert on restart.
+	BalanceMode string `json:"balanceMode,omitempty"`
 }

 // Forward is a rendered link row attached to a remote.
@ -317,6 +328,7 @@ func (s *Store) migrate() error {
 			"transport_tls INTEGER NOT NULL DEFAULT 0",
 			"transport_pool INTEGER NOT NULL DEFAULT 0",
 			"transport_tls_server_name TEXT NOT NULL DEFAULT ''",
+			"usr TEXT NOT NULL DEFAULT ''",
 			"vhost_http_port INTEGER NOT NULL DEFAULT 0",
 			"admin_addr TEXT NOT NULL DEFAULT ''",
 			"admin_port INTEGER NOT NULL DEFAULT 0",
@ -471,7 +483,7 @@ func (s *Store) DeleteLocal(name string) error {
 // ---- Remotes ----

 func (s *Store) ListRemotes() ([]Remote, error) {
-	rows, err := s.db.Query("SELECT name, ip, port, token, url, enabled, transport_protocol, transport_tls, transport_pool, transport_tls_server_name, vhost_http_port, admin_addr, admin_port, admin_user, admin_password FROM remotes ORDER BY name")
+	rows, err := s.db.Query("SELECT name, ip, port, token, url, enabled, transport_protocol, transport_tls, transport_pool, transport_tls_server_name, usr, vhost_http_port, admin_addr, admin_port, admin_user, admin_password FROM remotes ORDER BY name")
 	if err != nil {
 		return nil, err
 	}
@ -480,7 +492,7 @@ func (s *Store) ListRemotes() ([]Remote, error) {
 	for rows.Next() {
 		var r Remote
 		var en, tls int
-		if err := rows.Scan(&r.Name, &r.IP, &r.Port, &r.Token, &r.URL, &en, &r.TransportProtocol, &tls, &r.TransportPool, &r.TransportTLSServerName, &r.VhostHTTPPort, &r.AdminAddr, &r.AdminPort, &r.AdminUser, &r.AdminPassword); err != nil {
+		if err := rows.Scan(&r.Name, &r.IP, &r.Port, &r.Token, &r.URL, &en, &r.TransportProtocol, &tls, &r.TransportPool, &r.TransportTLSServerName, &r.User, &r.VhostHTTPPort, &r.AdminAddr, &r.AdminPort, &r.AdminUser, &r.AdminPassword); err != nil {
 			return nil, err
 		}
 		r.Enabled = en != 0
@ -493,8 +505,8 @@ func (s *Store) ListRemotes() ([]Remote, error) {
 func (s *Store) GetRemote(name string) (Remote, bool) {
 	var r Remote
 	var en, tls int
-	row := s.db.QueryRow("SELECT name, ip, port, token, url, enabled, transport_protocol, transport_tls, transport_pool, transport_tls_server_name, vhost_http_port, admin_addr, admin_port, admin_user, admin_password FROM remotes WHERE name = ?", name)
-	if err := row.Scan(&r.Name, &r.IP, &r.Port, &r.Token, &r.URL, &en, &r.TransportProtocol, &tls, &r.TransportPool, &r.TransportTLSServerName, &r.VhostHTTPPort, &r.AdminAddr, &r.AdminPort, &r.AdminUser, &r.AdminPassword); err != nil {
+	row := s.db.QueryRow("SELECT name, ip, port, token, url, enabled, transport_protocol, transport_tls, transport_pool, transport_tls_server_name, usr, vhost_http_port, admin_addr, admin_port, admin_user, admin_password FROM remotes WHERE name = ?", name)
+	if err := row.Scan(&r.Name, &r.IP, &r.Port, &r.Token, &r.URL, &en, &r.TransportProtocol, &tls, &r.TransportPool, &r.TransportTLSServerName, &r.User, &r.VhostHTTPPort, &r.AdminAddr, &r.AdminPort, &r.AdminUser, &r.AdminPassword); err != nil {
 		return Remote{}, false
 	}
 	r.Enabled = en != 0
@ -504,9 +516,9 @@ func (s *Store) GetRemote(name string) (Remote, bool) {

 func (s *Store) UpsertRemote(r Remote) error {
 	_, err := s.db.Exec(
-		"INSERT INTO remotes(name, ip, port, token, url, enabled, transport_protocol, transport_tls, transport_pool, transport_tls_server_name, vhost_http_port, admin_addr, admin_port, admin_user, admin_password) VALUES(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?) "+
-			"ON CONFLICT(name) DO UPDATE SET ip=excluded.ip, port=excluded.port, token=excluded.token, url=excluded.url, enabled=excluded.enabled, transport_protocol=excluded.transport_protocol, transport_tls=excluded.transport_tls, transport_pool=excluded.transport_pool, transport_tls_server_name=excluded.transport_tls_server_name, vhost_http_port=excluded.vhost_http_port, admin_addr=excluded.admin_addr, admin_port=excluded.admin_port, admin_user=excluded.admin_user, admin_password=excluded.admin_password",
-		r.Name, r.IP, r.Port, r.Token, r.URL, boolToInt(r.Enabled), r.TransportProtocol, boolToInt(r.TransportTLS), r.TransportPool, r.TransportTLSServerName, r.VhostHTTPPort, r.AdminAddr, r.AdminPort, r.AdminUser, r.AdminPassword,
+		"INSERT INTO remotes(name, ip, port, token, url, enabled, transport_protocol, transport_tls, transport_pool, transport_tls_server_name, usr, vhost_http_port, admin_addr, admin_port, admin_user, admin_password) VALUES(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?) "+
+			"ON CONFLICT(name) DO UPDATE SET ip=excluded.ip, port=excluded.port, token=excluded.token, url=excluded.url, enabled=excluded.enabled, transport_protocol=excluded.transport_protocol, transport_tls=excluded.transport_tls, transport_pool=excluded.transport_pool, transport_tls_server_name=excluded.transport_tls_server_name, usr=excluded.usr, vhost_http_port=excluded.vhost_http_port, admin_addr=excluded.admin_addr, admin_port=excluded.admin_port, admin_user=excluded.admin_user, admin_password=excluded.admin_password",
+		r.Name, r.IP, r.Port, r.Token, r.URL, boolToInt(r.Enabled), r.TransportProtocol, boolToInt(r.TransportTLS), r.TransportPool, r.TransportTLSServerName, r.User, r.VhostHTTPPort, r.AdminAddr, r.AdminPort, r.AdminUser, r.AdminPassword,
 	)
 	return err
 }
@ -748,6 +760,13 @@ func (s *Store) Settings() (Settings, error) {
 	if err := json.Unmarshal([]byte(raw), &st); err != nil {
 		return Settings{AutoStartProfiles: true, RestartOnExit: true, RestartIntervalSeconds: 5}, nil
 	}
+	// BalanceMode lives in its own column (see UpdateSettings). Surface it here
+	// too so callers reading Settings get the effective value, but never let it
+	// overwrite the column on a write-back: UpdateSettings only mirrors a
+	// non-empty value, so an unrelated settings PUT cannot clear a UI choice.
+	if mode, ok, err := s.BalanceMode(); err == nil && ok {
+		st.BalanceMode = mode
+	}
 	return st, nil
 }

@ -760,7 +779,36 @@ func (s *Store) UpdateSettings(st Settings) error {
 		"INSERT INTO settings(key, value) VALUES('settings', ?) ON CONFLICT(key) DO UPDATE SET value=excluded.value",
 		string(raw),
 	)
-	return err
+	if err != nil {
+		return err
+	}
+	if mode := st.BalanceMode; mode != "" {
+		// Mirror into its own column for the same reason the other flagged
+		// fields have one: the settings JSON is rewritten wholesale, so a
+		// clustered field that rides that JSON would flip back and forth between
+		// nodes instead of converging.
+		if _, err := s.db.Exec(
+			"INSERT INTO settings(key, value) VALUES('balance_mode', ?) ON CONFLICT(key) DO UPDATE SET value=excluded.value",
+			mode,
+		); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// BalanceMode returns the stored load-balancing mode, and whether one was ever
+// stored (false = never configured here; the environment default applies).
+func (s *Store) BalanceMode() (string, bool, error) {
+	var v string
+	err := s.db.QueryRow("SELECT value FROM settings WHERE key = 'balance_mode'").Scan(&v)
+	if errors.Is(err, sql.ErrNoRows) {
+		return "", false, nil
+	}
+	if err != nil {
+		return "", false, err
+	}
+	return v, v != "", nil
 }

 // SetNodeKey persists just the cluster admission key, preserving all other
--- a/internal/store/store_test.go
+++ b/internal/store/store_test.go
@ -58,3 +58,63 @@ func TestReplaceLinksClearsOld(t *testing.T) {
 		t.Fatalf("links = %+v", links)
 	}
 }
+
+// `usr` is a reserved SQL keyword in several dialects, so the remotes column is
+// named `usr`. This guards the mapping in both directions, including the
+// migrate() path that adds the column to pre-existing databases.
+func TestRemoteUserRoundTrip(t *testing.T) {
+	st, err := New(filepath.Join(t.TempDir(), "test.db"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer st.Close()
+
+	// A remote written without user (existing installs) must read back empty.
+	if err := st.UpsertRemote(Remote{Name: "plain", IP: "1.2.3.4", Port: 7000, Enabled: true}); err != nil {
+		t.Fatal(err)
+	}
+	if got, ok := st.GetRemote("plain"); !ok || got.User != "" {
+		t.Fatalf("plain remote user = %q ok=%v, want empty", got.User, ok)
+	}
+
+	want := Remote{Name: "panel", IP: "103.40.13.126", Port: 59999, Token: "tk", User: "e8f52adfaf0e5c95", Enabled: true}
+	if err := st.UpsertRemote(want); err != nil {
+		t.Fatal(err)
+	}
+	got, ok := st.GetRemote("panel")
+	if !ok || got.User != want.User {
+		t.Fatalf("user not persisted: %+v", got)
+	}
+	list, err := st.ListRemotes()
+	if err != nil {
+		t.Fatal(err)
+	}
+	var found bool
+	for _, r := range list {
+		if r.Name == "panel" {
+			found = true
+			if r.User != want.User {
+				t.Fatalf("ListRemotes user = %q, want %q", r.User, want.User)
+			}
+		}
+	}
+	if !found {
+		t.Fatal("panel remote missing from ListRemotes")
+	}
+
+	// Updating in place must not drop the column, and clearing it must work.
+	want.Token = "tk2"
+	if err := st.UpsertRemote(want); err != nil {
+		t.Fatal(err)
+	}
+	if got, _ := st.GetRemote("panel"); got.User != want.User || got.Token != "tk2" {
+		t.Fatalf("upsert lost fields: %+v", got)
+	}
+	want.User = ""
+	if err := st.UpsertRemote(want); err != nil {
+		t.Fatal(err)
+	}
+	if got, _ := st.GetRemote("panel"); got.User != "" {
+		t.Fatalf("user not cleared: %q", got.User)
+	}
+}
--- a/internal/version/version.go
+++ b/internal/version/version.go
@ -2,11 +2,11 @@
 //
 // Value is overridable at build time so release artifacts carry the real tag:
 //
-//	go build -ldflags="-X webui4frpc/internal/version.Version=0.1.3" ./cmd/webui4frpc
+//	go build -ldflags="-X webui4frpc/internal/version.Version=0.2.0" ./cmd/webui4frpc
 //
 // Kept in its own package because both cmd/ and internal/httpapi report it
 // (main can't be imported, and httpapi must not depend on cmd).
 package version

 // Version is the running build's semantic version, without a leading "v".
-var Version = "0.1.3"
+var Version = "0.2.0"
--- a/packaging/common/config.json
+++ b/packaging/common/config.json
@ -0,0 +1,27 @@
+{
+  "_comment": [
+    "webui4frpc startup config. Every field is optional; the effective",
+    "precedence is: command-line flag > this file > built-in default.",
+    "",
+    "Password handling (pick ONE, do not put a literal password here):",
+    "  \"password\": \"file:/etc/webui4frpc/secret/password\"   first line of a 0640 root:webui4frpc file",
+    "  \"password\": \"${W4F_PASSWORD}\"                        from the environment (unset => refuses to start)",
+    "",
+    "Unknown keys are a hard error, so a typo cannot silently fall back to the",
+    "built-in default credentials. The file may be absent (pure-flag mode)."
+  ],
+  "addr": "0.0.0.0:7500",
+  "user": "admin",
+  "password": "file:/etc/webui4frpc/secret/password",
+  "workdir": "/var/lib/webui4frpc",
+
+  "_optional": [
+    "bin     - initial frpc binary path, seeded into settings on first start",
+    "frpc    - fallback worker frpc path when settings has none",
+    "peers   - cluster peer host:port list (same as repeating -peer)",
+    "join_key- cluster admission key = sponsor node's nodeKey (or ${W4F_JOIN_KEY})"
+  ],
+  "frpc": "",
+  "peers": [],
+  "join_key": ""
+}
--- a/packaging/common/webui4frpc.env
+++ b/packaging/common/webui4frpc.env
@ -1,8 +1,28 @@
-# webui4frpc runtime configuration
-# 默认监听全部接口的 7500 端口；请修改密码后再投入生产。
-W4F_ADDR=0.0.0.0:7500
-W4F_USER=admin
-W4F_PASSWORD=admin
+# webui4frpc optional environment file.
+#
+# Listening address, admin credentials, workdir and peers now belong in
+# /etc/webui4frpc/config.json — that file is what systemd passes via
+# `webui4frpc -config ...`, and it keeps the password out of the unit file and
+# out of `ps` output.
+#
+# Everything here is OPTIONAL; the unit uses `EnvironmentFile=-`, so this file
+# may be empty or missing entirely.
+#
+# Referenced by config.json as ${VAR} (the variable must be set and non-empty,
+# otherwise startup fails loudly rather than booting with an empty password):
+# W4F_PASSWORD=change-me
+#
+# Cluster admission key, used by config.json as "join_key": "${W4F_JOIN_KEY}".
+# W4F_JOIN_KEY=
+#
+# Overrides the advertised hostname for peers (container DNS / wildcard listen).
+# W4F_HOST=
+#
+# Load balancing defaults (the per-node switch in the UI wins over these).
+# W4F_BALANCE_MODE=dry-run
+# W4F_BALANCE_COOLDOWN=600
+# W4F_BALANCE_INTERVAL=10

-# 可选：首次提供的 frpc 二进制路径（留空则从 Web UI 手动/自动安装）
-# W4F_FRPC=/usr/local/bin/frpc
+# Optional: point at a config file outside /etc/webui4frpc. An explicit
+# -config flag still wins over this.
+# W4F_CONFIG=/etc/webui4frpc/config.json
--- a/packaging/common/webui4frpc.service
+++ b/packaging/common/webui4frpc.service
@ -8,8 +8,15 @@ Wants=network-online.target
 Type=simple
 User=webui4frpc
 Group=webui4frpc
-EnvironmentFile=/etc/webui4frpc/webui4frpc.env
-ExecStart=/usr/bin/webui4frpc -addr ${W4F_ADDR} -user ${W4F_USER} -password ${W4F_PASSWORD} -workdir /var/lib/webui4frpc
+# The listening address, admin credentials and cluster peers live in
+# config.json, NOT on the command line: anything in ExecStart is visible to
+# every user via `ps` and in the unit file itself. Keep the password out of
+# this unit — put it in config.json as "file:/etc/webui4frpc/secret/password"
+# (or "${W4F_PASSWORD}" with an EnvironmentFile), never as -password.
+# The leading "-" makes the EnvironmentFile optional, so a node that keeps all
+# settings in config.json still starts.
+EnvironmentFile=-/etc/webui4frpc/webui4frpc.env
+ExecStart=/usr/bin/webui4frpc -config /etc/webui4frpc/config.json
 Restart=always
 RestartSec=5
 LimitNOFILE=65535
@ -20,6 +27,10 @@ PrivateTmp=true
 ProtectSystem=full
 ProtectHome=true
 ReadWritePaths=/var/lib/webui4frpc
+# config.json may point at a root-only secrets file for the admin password.
+# That path needs to be readable by this service account; keep such files in
+# /etc/webui4frpc/secret/ with mode 0640 root:webui4frpc.
+ReadOnlyPaths=-/etc/webui4frpc/secret

 [Install]
 WantedBy=multi-user.target
--- a/packaging/deb/postinst
+++ b/packaging/deb/postinst
@ -18,6 +18,16 @@ chmod 750 /var/lib/webui4frpc
 chown root:webui4frpc /etc/webui4frpc/webui4frpc.env 2>/dev/null || true
 chmod 640 /etc/webui4frpc/webui4frpc.env 2>/dev/null || true

+# Startup config + the directory that holds the admin password file.
+# The service reads /etc/webui4frpc/config.json (see the unit's ExecStart), so
+# the password never has to appear on the command line. secret/ is root-writable
+# and group-readable by the service account; files inside are created by the
+# admin, we only fix ownership/permissions of the directory itself.
+mkdir -p /etc/webui4frpc/secret
+chown root:webui4frpc /etc/webui4frpc/secret 2>/dev/null || true
+chmod 750 /etc/webui4frpc/secret 2>/dev/null || true
+chmod 644 /etc/webui4frpc/config.json 2>/dev/null || true
+
 if command -v systemctl >/dev/null 2>&1; then
    systemctl daemon-reload || true
    systemctl enable webui4frpc.service || true
@ -30,7 +40,8 @@ cat <<'EOF'

 webui4frpc 已安装。

-  配置:  /etc/webui4frpc/webui4frpc.env   (请立即修改 W4F_USER / W4F_PASSWORD)
+  配置:  /etc/webui4frpc/config.json      (请设置 password，推荐 file:/etc/webui4frpc/secret/password)
+  密钥:  echo '你的口令' > /etc/webui4frpc/secret/password && chmod 0640 /etc/webui4frpc/secret/password
  数据:  /var/lib/webui4frpc
  服务:  systemctl status webui4frpc
  界面:  http://<本机地址>:7500
--- a/packaging/macos/build_pkg.sh
+++ b/packaging/macos/build_pkg.sh
@ -38,15 +38,25 @@ mkdir -p "$ROOT/usr/local/bin" "$ROOT/usr/local/etc/webui4frpc" "$SCRIPTS" "$PKG
 # ---- payload 根文件系统 ----
 install -m 0755 "$BINARY" "$ROOT/usr/local/bin/webui4frpc"

-cat > "$ROOT/usr/local/etc/webui4frpc/webui4frpc.env" <<'ENVEOF'
-# webui4frpc runtime configuration (macOS)
-# 请修改密码后再投入使用；改完执行:
-#   sudo launchctl kickstart -k system/com.jianfeeeee.webui4frpc
-W4F_ADDR=0.0.0.0:7500
-W4F_USER=admin
-W4F_PASSWORD=admin
-ENVEOF
-chmod 0644 "$ROOT/usr/local/etc/webui4frpc/webui4frpc.env"
+# Startup config. The service reads this file via `-config`, so the admin
+# password never appears on the command line (visible in `ps` to every user).
+# Set the password in /usr/local/etc/webui4frpc/secret/password instead of
+# writing it here; the "file:" reference below reads its first line.
+mkdir -p "$ROOT/usr/local/etc/webui4frpc/secret"
+cat > "$ROOT/usr/local/etc/webui4frpc/config.json" <<'CFGEOF'
+{
+  "_comment": "precedence: command-line flag > this file > built-in default",
+  "addr": "0.0.0.0:7500",
+  "user": "admin",
+  "password": "file:/usr/local/etc/webui4frpc/secret/password",
+  "workdir": "/usr/local/var/lib/webui4frpc"
+}
+CFGEOF
+chmod 0644 "$ROOT/usr/local/etc/webui4frpc/config.json"
+# Placeholder so the service starts out of the box (admin/admin). The
+# postinstall script removes it if the file was already customised.
+printf 'admin\n' > "$ROOT/usr/local/etc/webui4frpc/secret/password"
+chmod 0640 "$ROOT/usr/local/etc/webui4frpc/secret/password"

 # ---- launchd plist ----
 mkdir -p "$ROOT/Library/LaunchDaemons"
@ -80,18 +90,15 @@ chmod 0644 "$ROOT/Library/LaunchDaemons/com.jianfeeeee.webui4frpc.plist"
 # launchd 不读 EnvironmentFile，用小包装脚本 source 配置再 exec
 cat > "$ROOT/usr/local/bin/webui4frpc-launch" <<'LAUNCHEOF'
 #!/bin/sh
-# 读取 /usr/local/etc/webui4frpc/webui4frpc.env 后启动 webui4frpc
+# Start webui4frpc from /usr/local/etc/webui4frpc/config.json.
+# launchd does not read an EnvironmentFile, so the optional env file is sourced
+# here first (config.json may reference ${W4F_*}), then the config file drives
+# everything. No credential is ever passed on this command line.
 set -e
 ENV_FILE=/usr/local/etc/webui4frpc/webui4frpc.env
-W4F_ADDR=0.0.0.0:7500
-W4F_USER=admin
-W4F_PASSWORD=admin
+CONFIG_FILE=/usr/local/etc/webui4frpc/config.json
 [ -f "$ENV_FILE" ] && . "$ENV_FILE"
-exec /usr/local/bin/webui4frpc \
-    -addr "$W4F_ADDR" \
-    -user "$W4F_USER" \
-    -password "$W4F_PASSWORD" \
-    -workdir /usr/local/var/lib/webui4frpc
+exec /usr/local/bin/webui4frpc -config "$CONFIG_FILE"
 LAUNCHEOF
 chmod 0755 "$ROOT/usr/local/bin/webui4frpc-launch"

@ -159,12 +166,16 @@ cat > "$FLAT/Distribution" <<DISTEOF
    <welcome language="zh_CN" mime-type="text/plain">webui4frpc — 可视化 frpc 控制器

 安装内容：
-  /usr/local/bin/webui4frpc                 主程序（内嵌 Web 界面）
-  /usr/local/etc/webui4frpc/webui4frpc.env  配置文件
-  /Library/LaunchDaemons/…webui4frpc.plist  开机自启服务
+  /usr/local/bin/webui4frpc                       主程序（内嵌 Web 界面）
+  /usr/local/etc/webui4frpc/config.json           启动配置（监听地址/账号/对端）
+  /usr/local/etc/webui4frpc/secret/password       口令文件（file: 引用，不进命令行）
+  /usr/local/etc/webui4frpc/webui4frpc.env        可选环境变量（config.json 里可写 \${VAR}）
+  /Library/LaunchDaemons/…webui4frpc.plist        开机自启服务

 安装完成后服务自动启动，访问 http://127.0.0.1:7500
-默认凭据 admin/admin —— 请立即修改 webui4frpc.env 中的密码。</welcome>
+默认凭据 admin/admin —— 请立即修改
+/usr/local/etc/webui4frpc/secret/password 后再重启
+（sudo launchctl kickstart -k system/com.jianfeeeee.webui4frpc）。</welcome>
    <choices-outline>
        <line choice="default">
            <line choice="com.jianfeeeee.webui4frpc"/>
--- a/packaging/rpm/webui4frpc.spec
+++ b/packaging/rpm/webui4frpc.spec
@ -1,5 +1,5 @@
 Name:           webui4frpc
-Version:        %{?_w4f_version}%{!?_w4f_version:0.1.3}
+Version:        %{?_w4f_version}%{!?_w4f_version:0.2.0}
 Release:        1%{?dist}
 Summary:        Visual frpc controller with token-ring cluster
 License:        MIT
@ -20,6 +20,8 @@ and audit-log CSV export.
 install -D -m 0755 %{_w4f_bin}          %{buildroot}%{_bindir}/webui4frpc
 install -D -m 0644 %{_w4f_service}      %{buildroot}%{_unitdir}/webui4frpc.service
 install -D -m 0640 %{_w4f_env}          %{buildroot}%{_sysconfdir}/webui4frpc/webui4frpc.env
+install -D -m 0644 %{_w4f_config}       %{buildroot}%{_sysconfdir}/webui4frpc/config.json
+install -d -m 0750                      %{buildroot}%{_sysconfdir}/webui4frpc/secret
 install -D -m 0644 %{_w4f_readme}       %{buildroot}%{_docdir}/webui4frpc/README.md
 install -d -m 0750                      %{buildroot}%{_sharedstatedir}/webui4frpc

@ -36,11 +38,14 @@ exit 0
 %systemd_post webui4frpc.service
 chown -R webui4frpc:webui4frpc %{_sharedstatedir}/webui4frpc || :
 chown root:webui4frpc %{_sysconfdir}/webui4frpc/webui4frpc.env || :
+chown root:webui4frpc %{_sysconfdir}/webui4frpc/secret || :
+chmod 0750 %{_sysconfdir}/webui4frpc/secret || :
 cat <<'EOF'

 webui4frpc 已安装。

-  配置:  /etc/webui4frpc/webui4frpc.env   (请立即修改 W4F_USER / W4F_PASSWORD)
+  配置:  /etc/webui4frpc/config.json      (请设置 password，推荐 file:/etc/webui4frpc/secret/password)
+  密钥:  echo '你的口令' > /etc/webui4frpc/secret/password && chmod 0640 /etc/webui4frpc/secret/password
  数据:  /var/lib/webui4frpc
  服务:  systemctl enable --now webui4frpc
  界面:  http://<本机地址>:7500
@ -63,10 +68,26 @@ fi
 %{_unitdir}/webui4frpc.service
 %dir %{_sysconfdir}/webui4frpc
 %config(noreplace) %attr(0640,root,webui4frpc) %{_sysconfdir}/webui4frpc/webui4frpc.env
+%config(noreplace) %attr(0644,root,root) %{_sysconfdir}/webui4frpc/config.json
+%dir %attr(0750,root,webui4frpc) %{_sysconfdir}/webui4frpc/secret
 %dir %attr(0750,webui4frpc,webui4frpc) %{_sharedstatedir}/webui4frpc
 %doc %{_docdir}/webui4frpc/README.md

 %changelog
+* Fri Oct 23 2026 JianFeeeee <jianfeeeee@gitcode> - 0.2.0-1
+- 从配置文件启动：新增 internal/appconfig，-config 指定配置文件（默认 <workdir>/config.json，$W4F_CONFIG 兜底）
+- 从配置文件启动：优先级 flag > 文件 > 内置默认，仅显式传入的 flag 参与覆盖
+- 从配置文件启动：支持 ${ENV} 与 file:<path> 两种密钥引用，口令/join-key 在日志与启动摘要中固定脱敏
+- 从配置文件启动：未配口令保持旧行为并打 WARNING；文件 JSON 损坏或含未知键则报错退出（防口令拼错静默回落）
+- 打包：systemd 单元与 deb/rpm/pkg/NSIS 全部改为 ExecStart=-config /etc/webui4frpc/config.json，命令行不再出现口令
+- 修复渲染：useEncryption/useCompression/bandwidthLimit 内嵌进 proxy 的 transport 对象（此前渲染在顶层，frpc --strict-config 拒载）
+- 新增 frpc 全局 user 字段（store 列名 usr，自动加列迁移），支持面板型 frps 强制 user 登录
+- 前端：RemoteNode 画布与 StatusView 表单新增 user 输入，带「面板型 frps 必填」提示
+* Mon Oct 06 2026 JianFeeeee <jianfeeeee@gitcode> - 0.1.4-1
+- 负载均衡：改为每节点自主释放（持有数超过平摊份额且 >=2 时自撤销一条丢回环，由最闲节点认领），不再由 leader 统一调度
+- 负载均衡：新增自限上界与下限（撤到平摊值即停、低于 2 条不撤），10 分钟冷却，默认不动作（dry-run）
+- 集群页：新增负载均衡视图与每节点模式开关（关闭/观察/启用），模式持久化
+- 新增只读接口 GET /cluster/balance 与写接口 POST /cluster/balance/mode
 * Sun Oct 05 2026 JianFeeeee <jianfeeeee@gitcode> - 0.1.3-1
 - 窄屏布局：补 box-sizing 重置、接管画布 fit（缩放下限 0.65）、弹窗宽度钳制、统一滚动容器（修复手机端整页无法滑动）
 - 集群：停用/启动改为经令牌环跨节点传播，撤销不再静默失效
--- a/packaging/windows/README.md
+++ b/packaging/windows/README.md
@ -79,7 +79,7 @@ cd web && npm run build && rm -rf internal/httpapi/dist && cp -r web/dist intern
 ### Linux (Debian / Ubuntu)

 ```bash
-sudo dpkg -i webui4frpc-0.1.1-linux-amd64.deb   # 或 linux-arm64.deb
+sudo dpkg -i webui4frpc-0.2.0-linux-amd64.deb   # 或 linux-arm64.deb
 sudo nano /etc/webui4frpc/webui4frpc.env        # 改掉默认密码
 sudo systemctl restart webui4frpc
 ```
@ -87,7 +87,7 @@ sudo systemctl restart webui4frpc
 ### Linux (RHEL / Fedora / openEuler / 默认 / 龙蜥)

 ```bash
-sudo rpm -i webui4frpc-0.1.1-linux-x86_64.rpm
+sudo rpm -i webui4frpc-0.2.0-linux-x86_64.rpm
 sudo vi /etc/webui4frpc/webui4frpc.env
 sudo systemctl enable --now webui4frpc
 ```
@ -97,7 +97,7 @@ sudo systemctl enable --now webui4frpc

 ### Windows

-双击 `webui4frpc-0.1.1-windows-amd64-setup.exe`（ARM 设备用 `windows-arm64-setup.exe`）。
+双击 `webui4frpc-0.2.0-windows-amd64-setup.exe`（ARM 设备用 `windows-arm64-setup.exe`）。
 安装向导会询问监听地址与管理员凭据，完成后：

 - 程序装到 `C:\Program Files\webui4frpc`
@ -107,8 +107,8 @@ sudo systemctl enable --now webui4frpc
 ### macOS

 ```bash
-sudo installer -pkg webui4frpc-0.1.1-darwin-arm64.pkg -target /   # Apple Silicon
-sudo installer -pkg webui4frpc-0.1.1-darwin-amd64.pkg -target /   # Intel
+sudo installer -pkg webui4frpc-0.2.0-darwin-arm64.pkg -target /   # Apple Silicon
+sudo installer -pkg webui4frpc-0.2.0-darwin-amd64.pkg -target /   # Intel
 ```

 或直接双击 `.pkg` 走图形安装器。安装后 launchd 开机自启，配置在
@ -126,7 +126,7 @@ sudo launchctl kickstart -k system/com.jianfeeeee.webui4frpc
 不想装服务只想跑一下，用对应的 `.tar.gz` / `.zip`，解压即用：

 ```bash
-tar xzf webui4frpc-0.1.1-linux-amd64.tar.gz
+tar xzf webui4frpc-0.2.0-linux-amd64.tar.gz
 ./webui4frpc -addr 127.0.0.1:7500 -user admin -password 你的密码 -workdir ./data
 ```

--- a/packaging/windows/webui4frpc.nsi
+++ b/packaging/windows/webui4frpc.nsi
@ -5,6 +5,10 @@

 !include "MUI2.nsh"
 !include "LogicLib.nsh"
+!include "StrFunc.nsh"
+
+; Used to JSON-escape the free-text fields written into config.json below.
+${Using:StrFunc} StrRep

 !ifndef VERSION
  !define VERSION "0.0.0"
@ -48,6 +52,9 @@ Var TxtPass
 Var CfgAddr
 Var CfgUser
 Var CfgPass
+Var EscAddr
+Var EscUser
+Var EscDir

 Function .onInit
  StrCpy $CfgAddr "0.0.0.0:7500"
@ -95,12 +102,37 @@ Section "webui4frpc" SecMain

  CreateDirectory "$INSTDIR\data"

-  ; 启动脚本，承载安装时选择的配置
+  ; ---- 启动配置 ----
+  ; 口令写进独立文件、由 config.json 用 "file:" 引用：既不出现在启动脚本的
+  ; 命令行上（任务管理器 / wmic 可见），也不需要做 JSON 转义。
+  ${StrRep} $EscDir $INSTDIR "\" "\\"
+  ${StrRep} $EscAddr $CfgAddr "\" "\\"
+  ${StrRep} $EscAddr $EscAddr '$\"' '\"'
+  ${StrRep} $EscUser $CfgUser "\" "\\"
+  ${StrRep} $EscUser $EscUser '$\"' '\"'
+
+  FileOpen $1 "$INSTDIR\secret-password.txt" w
+  FileWrite $1 "$CfgPass$\r$\n"
+  FileClose $1
+  ; 口令文件仅 SYSTEM / Administrators 可读（Program Files 默认 Users 可读）
+  nsExec::ExecToLog 'icacls "$INSTDIR\secret-password.txt" /inheritance:r /grant:r *S-1-5-18:F *S-1-5-32-544:F'
+
+  FileOpen $2 "$INSTDIR\data\config.json" w
+  FileWrite $2 "{$\r$\n"
+  FileWrite $2 '  "addr": "$EscAddr",$\r$\n'
+  FileWrite $2 '  "user": "$EscUser",$\r$\n'
+  FileWrite $2 '  "password": "file:$EscDir\\secret-password.txt",$\r$\n'
+  FileWrite $2 '  "workdir": "data"$\r$\n'
+  FileWrite $2 "}$\r$\n"
+  FileClose $2
+
+  ; 启动脚本：只传 -config，不传任何凭据
  FileOpen $0 "$INSTDIR\start-webui4frpc.cmd" w
  FileWrite $0 "@echo off$\r$\n"
  FileWrite $0 "rem webui4frpc 启动脚本（由安装程序生成）$\r$\n"
+  FileWrite $0 "rem 凭据在 data\config.json（口令来自 secret-password.txt），不经过命令行。$\r$\n"
  FileWrite $0 "cd /d %~dp0$\r$\n"
-  FileWrite $0 'webui4frpc.exe -addr $CfgAddr -user $CfgUser -password $CfgPass -workdir "%~dp0data"$\r$\n'
+  FileWrite $0 'webui4frpc.exe -config "%~dp0data\config.json"$\r$\n'
  FileClose $0

  WriteRegStr HKLM "Software\webui4frpc" "InstallDir" "$INSTDIR"
@ -142,6 +174,8 @@ Section "Uninstall"

  Delete "$INSTDIR\webui4frpc.exe"
  Delete "$INSTDIR\start-webui4frpc.cmd"
+  Delete "$INSTDIR\secret-password.txt"
+  Delete "$INSTDIR\data\config.json"
  Delete "$INSTDIR\README.md"
  Delete "$INSTDIR\LICENSE.txt"
  Delete "$INSTDIR\uninstall.exe"
--- a/scripts/build_installers.sh
+++ b/scripts/build_installers.sh
@ -12,7 +12,7 @@
 # 在 release.sh 流程内被调用；依赖 dist/artifacts/<version>/bin/<os>-<arch>/ 下的二进制。
 set -euo pipefail

-VERSION="${1:-0.1.3}"
+VERSION="${1:-0.2.0}"
 VERSION="${VERSION#v}"
 ROOT="$(cd "$(dirname "$0")/.." && pwd)"
 OUT="$ROOT/dist/artifacts/$VERSION"
@ -46,6 +46,8 @@ EOF
  install -m 0755 "$bindir/webui4frpc"            "$deb/usr/bin/webui4frpc"
  install -m 0644 "$PKG/common/webui4frpc.service" "$deb/lib/systemd/system/webui4frpc.service"
  install -m 0640 "$PKG/common/webui4frpc.env"     "$deb/etc/webui4frpc/webui4frpc.env"
+  install -m 0644 "$PKG/common/config.json"        "$deb/etc/webui4frpc/config.json"
+  install -d -m 0750                               "$deb/etc/webui4frpc/secret"
  install -m 0644 "$ROOT/README.md"                "$deb/usr/share/doc/webui4frpc/README.md"
  cat > "$deb/usr/share/doc/webui4frpc/copyright" <<'EOF'
 webui4frpc - visual frpc controller
@ -55,7 +57,7 @@ EOF
  install -m 0755 "$PKG/deb/postinst" "$deb/DEBIAN/postinst"
  install -m 0755 "$PKG/deb/prerm"    "$deb/DEBIAN/prerm"
  install -m 0755 "$PKG/deb/postrm"   "$deb/DEBIAN/postrm"
-  echo "/etc/webui4frpc/webui4frpc.env" > "$deb/DEBIAN/conffiles"
+  printf '%s\n' /etc/webui4frpc/webui4frpc.env /etc/webui4frpc/config.json > "$deb/DEBIAN/conffiles"
  ( cd "$deb" && find usr etc lib -type f -exec md5sum {} \; > DEBIAN/md5sums )
  dpkg-deb -b --root-owner-group "$deb" "$OUT/webui4frpc-${VERSION}-linux-${arch}.deb" >/dev/null
  echo "  ✔ .deb linux/$arch"
@ -74,6 +76,7 @@ build_rpm() {
    --define "_w4f_bin $bindir/webui4frpc" \
    --define "_w4f_service $PKG/common/webui4frpc.service" \
    --define "_w4f_env $PKG/common/webui4frpc.env" \
+    --define "_w4f_config $PKG/common/config.json" \
    --define "_w4f_readme $ROOT/README.md" \
    --define "_unitdir /usr/lib/systemd/system" \
    --define "_sharedstatedir /var/lib" >/tmp/w4f-rpm.log 2>&1 || true
--- a/scripts/criteria/config-startup.sh
+++ b/scripts/criteria/config-startup.sh
@ -0,0 +1,135 @@
+#!/bin/bash
+# 判据：webui4frpc 支持从配置文件启动，且口令不泄漏。
+#
+# 覆盖三件事：
+#   1. go build ./... 与 go test ./... 全绿（含配置文件优先级的回归测试）；
+#   2. 优先级 显式 flag > 配置文件 > 内置默认值 —— 未显式传的 flag 不得用
+#      默认值压过配置文件；
+#   3. 用配置文件（file: 引用口令）启动后，明文口令既不出现在进程命令行，
+#      也不出现在启动日志；坏 JSON 必须非零退出，文件缺失必须能正常启动。
+#
+# 退出码 0 = 通过。
+set -u
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+cd "$ROOT" || { echo "FAIL: 无法进入仓库根 $ROOT"; exit 1; }
+WORK="$(mktemp -d)"
+PIDS=()
+cleanup() { for p in "${PIDS[@]:-}"; do kill "$p" 2>/dev/null; done; wait 2>/dev/null; rm -rf "$WORK"; }
+trap cleanup EXIT
+fail() { echo "FAIL: $*"; exit 1; }
+
+# 取一个空闲端口。判据里必须用随机空闲端口：默认 127.0.0.1:7500 上通常已有
+# 生产实例在跑，端口冲突造成的非零退出会被误判成"配置错误已正确报错"。
+free_port() {
+  python3 -c 'import socket
+s = socket.socket(); s.bind(("127.0.0.1", 0)); print(s.getsockname()[1]); s.close()'
+}
+
+# 断言：进程在配置文件非法时"没进入监听"就必须死。
+# 只检查退出码不够——错误串里本来就含 "invalid JSON"，实现把 Fatal 改成
+# 打日志后继续跑，退出码可能因为端口冲突等原因仍非零。真正的判据是它不能再
+# 继续提供服务，所以出现 listening 日志即判失败。
+assert_died_before_listen() {
+  local log="$1" why="$2"
+  if grep -q 'listening on' "$log"; then
+    cat "$log"
+    fail "$why：配置错误被静默忽略后仍进入监听（应启动前就退出）"
+  fi
+}
+
+# ---- 0. 前端嵌入产物 ----
+# internal/httpapi 用 //go:embed all:dist 嵌入前端，而 dist 是构建期产物、
+# 被 .gitignore 排除。干净 clone 上不先构建前端，go build 会直接报
+# "pattern all:dist: no matching files found"——那是基线既有状态，与本判据
+# 无关，所以这里先补齐，让判据在任何 checkout 上都能复现。
+if [ ! -f internal/httpapi/dist/index.html ]; then
+  command -v npm >/dev/null 2>&1 \
+    || fail "缺少前端构建产物 internal/httpapi/dist 且没有 npm；请在有 node 的环境跑，或先手工 cd web && npm ci && npm run build && cp -r dist ../internal/httpapi/dist"
+  ( cd web \
+    && { [ -d node_modules ] || npm ci --no-audit --no-fund >/dev/null 2>&1; } \
+    && npm run build >/dev/null 2>&1 ) || fail "前端构建失败（cd web && npm run build）"
+  rm -rf internal/httpapi/dist && mkdir -p internal/httpapi/dist
+  cp -r web/dist/. internal/httpapi/dist/ || fail "拷贝前端产物失败"
+fi
+
+# ---- 1. 构建与全量测试 ----
+go build ./... || fail "go build ./..."
+go test ./... > "$WORK/test.log" 2>&1 || { cat "$WORK/test.log"; fail "go test ./..."; }
+
+# ---- 2. 优先级回归测试必须存在且通过 ----
+# 这是整个改动最容易做错的一点：Go 的 flag 默认值会无条件覆盖配置文件。
+go test ./internal/appconfig/ -count=1 \
+  -run 'TestResolveFileBeatsFlagDefaults|TestResolveExplicitFlagBeatsFile|TestLoadRejectsUnknownKey|TestSummaryRedactsSecrets' \
+  > "$WORK/appconfig.log" 2>&1 || { cat "$WORK/appconfig.log"; fail "appconfig 优先级/脱敏回归测试未通过"; }
+
+# ---- 3. 端到端：配置文件启动，口令不落到命令行与日志 ----
+BIN="$WORK/w4f"
+go build -o "$BIN" ./cmd/webui4frpc || fail "构建二进制失败"
+
+SECRET="CRIT_SECRET_${RANDOM}_9f3a"
+printf '%s\n' "$SECRET" > "$WORK/pw"
+chmod 600 "$WORK/pw"
+PORT="$(free_port)"
+python3 -c '
+import json, sys
+t, addr = sys.argv[1], sys.argv[2]
+json.dump({"addr": addr, "user": "crituser",
+           "password": "file:" + t + "/pw", "workdir": t + "/data"},
+          open(t + "/cfg.json", "w"))
+' "$WORK" "127.0.0.1:$PORT"
+
+# 注意：-config 只是路径，口令来自 file: 引用，命令行本身不含秘密。
+"$BIN" -config "$WORK/cfg.json" > "$WORK/run.log" 2>&1 &
+P=$!
+PIDS+=("$P")
+sleep 3
+kill -0 "$P" 2>/dev/null || { cat "$WORK/run.log"; fail "进程未能从配置文件启动"; }
+
+if tr '\0' ' ' < "/proc/$P/cmdline" | grep -q -- "$SECRET"; then
+  fail "明文口令出现在进程命令行（ps 可见）"
+fi
+if grep -q -- "$SECRET" "$WORK/run.log"; then
+  cat "$WORK/run.log"
+  fail "明文口令出现在启动日志"
+fi
+grep -q "listening on 127.0.0.1:$PORT" "$WORK/run.log" \
+  || { cat "$WORK/run.log"; fail "配置文件里的 addr 未生效（未在 $PORT 上监听）"; }
+kill "$P" 2>/dev/null; wait "$P" 2>/dev/null
+
+# ---- 4. 文件存在但 JSON 非法 -> 响亮报错退出 ----
+# 用 timeout 兜底：若实现退化成"只记日志继续启动"，进程会一直跑而不是报错，
+# 这里必须把它判成失败，不能把自己挂死。
+printf '{"addr":' > "$WORK/bad.json"
+timeout 10 "$BIN" -config "$WORK/bad.json" \
+  -addr "127.0.0.1:$(free_port)" -workdir "$WORK/d_bad" > "$WORK/bad.log" 2>&1
+rc=$?
+[ "$rc" -eq 124 ] && { cat "$WORK/bad.log"; fail "配置文件 JSON 非法时进程没有退出（静默忽略），判据要求响亮报错"; }
+[ "$rc" -eq 0 ] && { cat "$WORK/bad.log"; fail "配置文件 JSON 非法时应非零退出，实际正常退出"; }
+assert_died_before_listen "$WORK/bad.log" "JSON 非法"
+grep -qi 'invalid JSON' "$WORK/bad.log" || { cat "$WORK/bad.log"; fail "非法 JSON 的报错信息不明确"; }
+
+# ---- 5. 未知键（拼写错误）-> 报错退出，不得静默回落到默认口令 ----
+printf '{"passwd":"x"}' > "$WORK/typo.json"
+timeout 10 "$BIN" -config "$WORK/typo.json" \
+  -addr "127.0.0.1:$(free_port)" -workdir "$WORK/d_typo" > "$WORK/typo.log" 2>&1
+rc=$?
+[ "$rc" -eq 124 ] && { cat "$WORK/typo.log"; fail "未知键被静默忽略（进程继续运行），拼错的 password 会回落到默认值"; }
+[ "$rc" -eq 0 ] && { cat "$WORK/typo.log"; fail "未知键应被拒绝（否则拼错的 password 会静默使用默认值）"; }
+assert_died_before_listen "$WORK/typo.log" "未知键"
+
+# ---- 6. 配置文件缺失 -> 不算错误，回落到纯 flag 行为 ----
+"$BIN" -config "$WORK/none.json" -addr "127.0.0.1:$(free_port)" -workdir "$WORK/d2" > "$WORK/miss.log" 2>&1 &
+P2=$!
+PIDS+=("$P2")
+sleep 3
+kill -0 "$P2" 2>/dev/null || { cat "$WORK/miss.log"; fail "配置文件缺失时应回落到纯 flag 行为并正常启动"; }
+kill "$P2" 2>/dev/null; wait "$P2" 2>/dev/null
+
+# ---- 7. 交付的单元/示例配置不得携带明文口令 ----
+if grep -rn -- '-password' packaging/common/webui4frpc.service \
+     packaging/common/config.json scripts/release.sh 2>/dev/null \
+     | grep -v 'never as -password'; then
+  fail "打包产物（单元/示例配置/分发模板）仍含命令行口令"
+fi
+
+echo "OK: 配置文件启动与口令不泄漏的判据全部通过"
--- a/scripts/release.sh
+++ b/scripts/release.sh
@ -3,7 +3,7 @@
 # webui4frpc 多平台发布脚本
 #
 # 用法:
-#   ./scripts/release.sh [version]        # 默认 version=0.1.3
+#   ./scripts/release.sh [version]        # 默认 version=0.2.0
 #
 # 行为:
 #   1. 构建前端 (web/dist) 并同步到 internal/httpapi/dist (go:embed 用)
@ -19,7 +19,7 @@
 #   NO_BUILD_FRONTEND  设为 1 跳过前端构建 (用现有 dist)
 set -euo pipefail

-VERSION="${1:-0.1.3}"
+VERSION="${1:-0.2.0}"
 VERSION="${VERSION#v}"   # 去掉可能的前导 v
 ROOT="$(cd "$(dirname "$0")/.." && pwd)"
 OUT="$ROOT/dist/artifacts/$VERSION"
@ -92,7 +92,10 @@ Wants=network-online.target

 [Service]
 Type=simple
-ExecStart=/opt/webui4frpc/webui4frpc -addr 0.0.0.0:7500 -user admin -password admin -workdir /opt/webui4frpc/data
+# Listen address, admin credentials and peers live in config.json, not here:
+# whatever is in ExecStart is visible to every user via `ps`. Set the password
+# in /opt/webui4frpc/config.json as "file:/opt/webui4frpc/secret/password".
+ExecStart=/opt/webui4frpc/webui4frpc -config /opt/webui4frpc/config.json
 Restart=always
 RestartSec=5
 LimitNOFILE=65535
@ -121,7 +124,8 @@ for target in "${TARGETS[@]}"; do
    ( cd "$stage" && zip -q "$OUT/$base.zip" "$bin" README.md )
  else
    cp "$OUT/webui4frpc.service.tpl" "$stage/"
-    ( cd "$stage" && tar czf "$OUT/$base.tar.gz" "$bin" README.md webui4frpc.service.tpl )
+    cp "$ROOT/packaging/common/config.json" "$stage/config.json.example"
+    ( cd "$stage" && tar czf "$OUT/$base.tar.gz" "$bin" README.md webui4frpc.service.tpl config.json.example )
  fi
 done
 rm -rf "$OUT/.stage"
--- a/web/src/api.ts
+++ b/web/src/api.ts
@ -2,6 +2,7 @@
 import type {
 	ApiKey,
 	ApiKeyCreated,
+	BalanceReport,
 	BinaryStatus,
 	CacheResp,
 	CanvasData,
@ -159,6 +160,21 @@ export const api = {
 	// M6 token ring snapshot.
 	ring: () => request<RingSnapshot>("/api/manager/cluster/ring"),

+	// Load balancer read-only view. Reports per-node scores, whether anything is
+	// over the threshold, and the migration it would perform. Never mutates the
+	// cluster. 404 when the balancer is not wired up on that node.
+	balance: () => request<BalanceReport>("/api/manager/cluster/balance"),
+
+	// setBalanceMode switches load balancing on THIS node (off | dry-run | on).
+	// Per-node by design: each member releases only its own forwards, so there is
+	// no cluster-wide switch to flip. Requires write level.
+	setBalanceMode: (mode: string) =>
+		request<BalanceReport>("/api/manager/cluster/balance/mode", {
+			method: "POST",
+			headers: { "Content-Type": "application/json" },
+			body: JSON.stringify({ mode }),
+		}),
+
 	// M6 cluster lifecycle (创建/加入/退出/移除).
 	// clusterCreate: reseed THIS node as a fresh standalone leader (创建集群).
 	clusterCreate: () =>
--- a/web/src/components/RemoteNode.vue
+++ b/web/src/components/RemoteNode.vue
@ -51,6 +51,12 @@
        <label class="adv-sep">HTTP 访问端口 (frps vhostHTTPPort)</label>
        <label>vhostHTTPPort <input v-model.number="vhostHttpPortField" type="number" min="0" /></label>

+        <label class="adv-sep">用户标识 (frpc user)</label>
+        <label>user <input v-model="userField" :placeholder="userHint" /></label>
+        <div v-if="needsUser" class="user-warn">
+          面板型 frps 必须填 user，否则登录被拒（panel HTTP status 403）；留空则该项不出现在生成的配置里。
+        </div>
+
        <label class="adv-sep">本地 frpc 管理 API (M3)</label>
        <label class="adv-check">启用后状态页按真实代理状态展示
          <span class="hint-txt">(adminPort &gt; 0)</span>
@ -96,6 +102,7 @@ const portField = field('port')
 const tokenField = field('token')
 const urlField = field('url')
 const enabledField = field('enabled')
+const userField = field('user')
 const transportProtocolField = field('transportProtocol')
 const transportTlsField = field('transportTls')
 const transportTlsServerNameField = field('transportTlsServerName')
@ -106,6 +113,13 @@ const adminPortField = field('adminPort')
 const adminUserField = field('adminUser')
 const adminPasswordField = field('adminPassword')
 const showAdv = ref(false)
+
+// A panel-managed frps rejects password-only logins, so surface the field with
+// a hint instead of leaving the failure to a frpc log line nobody reads.
+const needsUser = computed(() => !String(userField.value || '').trim())
+const userHint = computed(() =>
+  needsUser.value ? '必填（面板型 frps）' : '与 frps 侧一致',
+)
 </script>

 <style scoped lang="scss">
@ -299,6 +313,14 @@ const showAdv = ref(false)
      border-top: 1px dashed var(--w4f-warn-border);
      padding-top: 4px;
    }
+
+    // warning shown while the required `user` field is still empty
+    .user-warn {
+      grid-column: 1 / -1;
+      font-size: 11px;
+      line-height: 1.4;
+      color: var(--w4f-warn-text);
+    }
  }
 }
 </style>
--- a/web/src/types.ts
+++ b/web/src/types.ts
@ -9,332 +9,388 @@ export type CanvasRemote = Remote;
 export type CanvasLink = Link;

 export interface Local {
-  name: string;
-  ip: string;
-  port: number;
-  protocol: string; // tcp | udp | http | https
-  // localOnly: forward stays on this node (loopback kept), no cluster.
-  localOnly?: boolean;
+	name: string;
+	ip: string;
+	port: number;
+	protocol: string; // tcp | udp | http | https
+	// localOnly: forward stays on this node (loopback kept), no cluster.
+	localOnly?: boolean;

-  // M1 advanced transport knobs (optional; empty/zero = frpc defaults)
-  useEncryption?: boolean;
-  useCompression?: boolean;
-  bandwidthLimit?: string;
-  poolCount?: number;
-  metadatas?: Record<string, string>;
-  annotations?: Record<string, string>;
+	// M1 advanced transport knobs (optional; empty/zero = frpc defaults)
+	useEncryption?: boolean;
+	useCompression?: boolean;
+	bandwidthLimit?: string;
+	poolCount?: number;
+	metadatas?: Record<string, string>;
+	annotations?: Record<string, string>;

-  // M2 HTTP/HTTPS routing (http/https only)
-  customDomains?: string; // comma-separated
-  subdomain?: string;
-  locations?: string[];
-  hostHeaderRewrite?: string;
-  httpHeaders?: Record<string, string>;
-  basicAuthUser?: string;
-  basicAuthPassword?: string;
+	// M2 HTTP/HTTPS routing (http/https only)
+	customDomains?: string; // comma-separated
+	subdomain?: string;
+	locations?: string[];
+	hostHeaderRewrite?: string;
+	httpHeaders?: Record<string, string>;
+	basicAuthUser?: string;
+	basicAuthPassword?: string;

-  // M3 load balancing group + health check
-  lbGroup?: string;
-  lbGroupKey?: string;
-  healthCheckType?: string; // "" | tcp | http
-  healthCheckPath?: string;
-  healthCheckTimeout?: number;
-  healthCheckMaxFailed?: number;
-  healthCheckInterval?: number;
+	// M3 load balancing group + health check
+	lbGroup?: string;
+	lbGroupKey?: string;
+	healthCheckType?: string; // "" | tcp | http
+	healthCheckPath?: string;
+	healthCheckTimeout?: number;
+	healthCheckMaxFailed?: number;
+	healthCheckInterval?: number;
 }

 export interface Remote {
-  name: string;
-  ip: string;
-  port: number; // frps connect port
-  token?: string;
-  url?: string;
-  enabled: boolean;
+	name: string;
+	ip: string;
+	port: number; // frps connect port
+	token?: string;
+	url?: string;
+	enabled: boolean;

-  // M1 transport section
-  transportProtocol?: string; // tcp | quic | kcp | websocket
-  transportTls?: boolean;
-  transportPool?: number;
-  transportTlsServerName?: string;
+	// M1 transport section
+	transportProtocol?: string; // tcp | quic | kcp | websocket
+	transportTls?: boolean;
+transportPool?: number;
+transportTlsServerName?: string;

-  // M2: frps vhostHTTPPort
-  vhostHttpPort?: number;
+	// user: frpc's global `user` field. frps prefixes every proxy name with it,
+	// and panel-managed frps requires it for login (otherwise the server answers
+	// `panel authentication unavailable: panel HTTP status 403`).
+	// Empty = omitted from the rendered config (plain frps).
+	user?: string;

-  // M3: local frpc admin API (webServer)
-  adminAddr?: string;
-  adminPort?: number;
-  adminUser?: string;
-  adminPassword?: string;
+	// M2: frps vhostHTTPPort
+	vhostHttpPort?: number;
+
+	// M3: local frpc admin API (webServer)
+	adminAddr?: string;
+	adminPort?: number;
+	adminUser?: string;
+	adminPassword?: string;
 }

 export interface Link {
-  id?: number;
-  local: string;
-  remote: string;
-  remotePort: number;
-  offsetX?: number;
-  offsetY?: number;
-  // group: management label for one-click group start/stop on the forwards
-  // page (unrelated to frps load-balancing lbGroup on Local).
-  group?: string;
-  // disabled: per-forward stop flag. A disabled forward is omitted from the
-  // frpc config (local) / left out of the ring topology (cluster), so stop is
-  // per-card and survives canvas re-saves.
-  disabled?: boolean;
+	id?: number;
+	local: string;
+	remote: string;
+	remotePort: number;
+	offsetX?: number;
+	offsetY?: number;
+	// group: management label for one-click group start/stop on the forwards
+	// page (unrelated to frps load-balancing lbGroup on Local).
+	group?: string;
+	// disabled: per-forward stop flag. A disabled forward is omitted from the
+	// frpc config (local) / left out of the ring topology (cluster), so stop is
+	// per-card and survives canvas re-saves.
+	disabled?: boolean;
 }

 export interface CanvasData {
-  locals: Local[];
-  remotes: Remote[];
-  links: Link[];
+	locals: Local[];
+	remotes: Remote[];
+	links: Link[];
 }

 export interface Settings {
-  autoStartProfiles: boolean;
-  restartOnExit: boolean;
-  restartIntervalSeconds: number;
-  binaryPath?: string;
+	autoStartProfiles: boolean;
+	restartOnExit: boolean;
+	restartIntervalSeconds: number;
+	binaryPath?: string;
 }

 export interface ProcessStatus {
-  state: string;
-  pid?: number;
-  startTime?: number;
-  restartCount: number;
-  exitCode?: number;
-  err?: string;
+	state: string;
+	pid?: number;
+	startTime?: number;
+	restartCount: number;
+	exitCode?: number;
+	err?: string;
 }

 export interface ProxyState {
-  name: string;
-  type: string;
-  status: string; // new | wait start | start error | running | check failed | closed
-  err?: string;
-  local_addr?: string;
-  remote_addr?: string;
+	name: string;
+	type: string;
+	status: string; // new | wait start | start error | running | check failed | closed
+	err?: string;
+	local_addr?: string;
+	remote_addr?: string;
 }

 export interface StatusProfile {
-  name: string;
-  enabled: boolean;
-  process: ProcessStatus;
-  hasProcess: boolean;
-  forwards: { service: string; remotePort: number; localPort?: number }[];
-  // connState: derived frps connection state (we do not control remote frps)
-  connState?: string; // connected | connecting | failed | not_started | disabled
-  // M3: admin API state
-  adminEnabled?: boolean;
-  proxyStates?: ProxyState[];
-  groupCount?: number;
+	name: string;
+	enabled: boolean;
+	process: ProcessStatus;
+	hasProcess: boolean;
+	forwards: { service: string; remotePort: number; localPort?: number }[];
+	// connState: derived frps connection state (we do not control remote frps)
+	connState?: string; // connected | connecting | failed | not_started | disabled
+	// M3: admin API state
+	adminEnabled?: boolean;
+	proxyStates?: ProxyState[];
+	groupCount?: number;
 }

 export interface StatusResp {
-  version: string;
-  workDir: string;
-  settings: Settings;
-  services: Local[];
-  remotes: Remote[];
-  binaryPath: string;
-  profiles: StatusProfile[];
-  localStatus: LocalStatus[];
-  // forwards: the forward-centric list rendered as cards on the status page.
-  forwards: ForwardStatus[];
-  // selfId: this node's ring ID (== SelfAddr), to tell whether a cluster
-  // forward's owner is this node (worker runs here) or a peer.
-  selfId: string;
+	version: string;
+	workDir: string;
+	settings: Settings;
+	services: Local[];
+	remotes: Remote[];
+	binaryPath: string;
+	profiles: StatusProfile[];
+	localStatus: LocalStatus[];
+	// forwards: the forward-centric list rendered as cards on the status page.
+	forwards: ForwardStatus[];
+	// selfId: this node's ring ID (== SelfAddr), to tell whether a cluster
+	// forward's owner is this node (worker runs here) or a peer.
+	selfId: string;
 }

 // ForwardStatus is one forward (link) in the forward-centric status view.
 // kind distinguishes 本地转发 (localOnly) from 远程转发 (cluster-distributed).
 export interface ForwardStatus {
-  local: string;
-  remote: string;
-  remotePort: number;
-  localOnly: boolean;
-  kind: "local" | "remote";
-  ownerId?: string; // remote = topology owner; local = selfId
-  active: boolean; // remote = in topology; local = local worker running
-  disabled: boolean; // per-forward stop flag (true = stopped)
-  group?: string;
-  localIp?: string;
-  localPort?: number;
-  localProto?: string;
+	local: string;
+	remote: string;
+	remotePort: number;
+	localOnly: boolean;
+	kind: "local" | "remote";
+	ownerId?: string; // remote = topology owner; local = selfId
+	active: boolean; // remote = in topology; local = local worker running
+	disabled: boolean; // per-forward stop flag (true = stopped)
+	group?: string;
+	localIp?: string;
+	localPort?: number;
+	localProto?: string;
 }

 export interface LocalTargetStatus {
-  remote: string;
-  remotePort: number;
-  workerState: string;
+	remote: string;
+	remotePort: number;
+	workerState: string;
 }

 export interface LocalStatus {
-  local: Local;
-  targets: LocalTargetStatus[];
+	local: Local;
+	targets: LocalTargetStatus[];
 }

 export interface BinaryStatus {
-  binaryPath: string;
-  version?: string;
+	binaryPath: string;
+	version?: string;
 }

 export interface InstallResult {
-  path: string;
-  version: string;
+	path: string;
+	version: string;
 }

 // M6: cluster node registry + binary cache.
 export interface ClusterNode {
-  addr: string;
-  cache?: string[];
-  version?: string;
+	addr: string;
+	cache?: string[];
+	version?: string;
 }

 export interface CacheEntry {
-  version: string;
-  path: string;
-  size: number;
-  modTime: number;
+	version: string;
+	path: string;
+	size: number;
+	modTime: number;
 }

 export interface ClusterNodesResp {
-  nodes: ClusterNode[];
+	nodes: ClusterNode[];
 }

 export interface CacheResp {
-  cache: CacheEntry[];
-  removed?: string[];
+	cache: CacheEntry[];
+	removed?: string[];
 }

 // M6 token-ring snapshot (GET /cluster/ring).
 export interface RingNode {
-  id: string;
-  addr: string;
-  isLeader?: boolean;
-  alive: boolean;
-  load: { memPct: number; netPct: number; forwards?: number };
-  version?: string;
-  cache?: string[];
-  lastSeen?: number;
+	id: string;
+	addr: string;
+	isLeader?: boolean;
+	alive: boolean;
+	load: { memPct: number; netPct: number; forwards?: number };
+	version?: string;
+	cache?: string[];
+	lastSeen?: number;
 }

 export interface RingTaskInfo {
-  id: string;
-  revoke?: boolean;
-  removeNode?: string; // node-removal command (target rides the token to self-remove)
-  local: { name: string };
-  remote: { name: string };
-  link: { remotePort?: number };
+	id: string;
+	revoke?: boolean;
+	removeNode?: string; // node-removal command (target rides the token to self-remove)
+	local: { name: string };
+	remote: { name: string };
+	link: { remotePort?: number };
 }

 export interface RingTopoEntry {
-  taskId: string;
-  ownerId: string;
-  active: boolean;
-  local: { name: string };
-  remote: { name: string };
-  link: { remotePort?: number };
+	taskId: string;
+	ownerId: string;
+	active: boolean;
+	local: { name: string };
+	remote: { name: string };
+	link: { remotePort?: number };
 }

 export interface RingLogEntry {
-  seq: number;
-  node: string;
-  kind: string;
-  at?: number;
-  data?: Record<string, any> | null;
+	seq: number;
+	node: string;
+	kind: string;
+	at?: number;
+	data?: Record<string, any> | null;
 }

 export interface RingSnapshot {
-  selfId: string;
-  leaderId: string; // 当前 leader（持首令牌 + 判丢失 + 被上家监控）
-  cycle: number; // 周期号（leader 每收令牌回 +1）
-  lastSync: number; // 上次同步时间 (unix sec)
-  roundDelayMs?: number;
-  nodes: RingNode[];
-  pending: RingTaskInfo[];
-  topology: RingTopoEntry[];
-  log: RingLogEntry[];
-  // nodeKey: this node's cluster admission key. Newcomers must present it to
-  // join via this node (handleClusterJoin verifies). Shown on the cluster page
-  // for the operator to copy; omitted for non-cluster (standalone) nodes.
-  nodeKey?: string;
+	selfId: string;
+	leaderId: string; // 当前 leader（持首令牌 + 判丢失 + 被上家监控）
+	cycle: number; // 周期号（leader 每收令牌回 +1）
+	lastSync: number; // 上次同步时间 (unix sec)
+	roundDelayMs?: number;
+	nodes: RingNode[];
+	pending: RingTaskInfo[];
+	topology: RingTopoEntry[];
+	log: RingLogEntry[];
+	// nodeKey: this node's cluster admission key. Newcomers must present it to
+	// join via this node (handleClusterJoin verifies). Shown on the cluster page
+	// for the operator to copy; omitted for non-cluster (standalone) nodes.
+	nodeKey?: string;
+}
+
+// BalanceReport is one node's own view of rebalancing (GET /cluster/balance).
+//
+// It is per-node by design: every member runs the same rule against its own
+// forwards, and the answer that matters is the one on the node doing (or
+// refusing to do) the releasing. So this reports "my share" first and the peers
+// second, and there is no cluster-wide "would migrate" plan — the ring's normal
+// lowest-load claim decides where a released forward lands.
+export interface BalanceReleasePlan {
+	local: string;
+	remote: string;
+	remotePort: number;
+	owner: string;
+}
+
+export interface BalanceReport {
+	mode: "off" | "dry-run" | "on";
+	modeSource: "env" | "stored"; // env = W4F_BALANCE_MODE default, stored = set here
+	enabled: boolean; // mode !== off
+	dryRun: boolean; // mode !== on
+	canControl: boolean; // this principal may switch it (write level)
+	isMember: boolean;
+	self: string;
+
+	selfForwards: number;
+	share: number; // the even split: ceil(total / alive)
+	totalForwards: number;
+	aliveNodes: number;
+	selfOverShare: boolean;
+
+	// wouldRelease is present whenever this node is over its share — including
+	// while it is deliberately holding back, which is what blockedBy explains.
+	wouldRelease?: BalanceReleasePlan;
+	releasing?: BalanceReleasePlan;
+	blockedBy?: string; // single-node | below-min | balanced | nothing-active | cooldown | in-flight
+
+	cooldownSec: number;
+	lastReleaseAt?: number;
+	nodes: BalanceNodeReport[];
+}
+
+export interface BalanceNodeReport {
+	id: string;
+	alive: boolean;
+	isLeader: boolean;
+	forwards: number;
+	memPct: number;
+	netPct: number;
+	score: number;
 }

 // ---- Auth / accounts / API keys (M7) ----

-export type AccessLevel = 'read' | 'write' | 'admin' | 'superadmin';
+export type AccessLevel = "read" | "write" | "admin" | "superadmin";

 // MeResp is the authenticated principal (GET /me). The frontend uses level to
 // gate the UI: viewer (= auditors) sees read + export controls only.
 export interface MeResp {
-  type: 'user' | 'service' | 'key';
-  name: string;
-  level: AccessLevel;
-  userId?: number;
+	type: "user" | "service" | "key";
+	name: string;
+	level: AccessLevel;
+	userId?: number;
 }

 export interface User {
-  id: number;
-  username: string;
-  role: 'admin' | 'viewer' | 'superadmin';
-  enabled: boolean;
-  system?: boolean; // flag-synced built-in account (UI read-only)
-  createdAt: number;
-  lastLoginAt: number;
+	id: number;
+	username: string;
+	role: "admin" | "viewer" | "superadmin";
+	enabled: boolean;
+	system?: boolean; // flag-synced built-in account (UI read-only)
+	createdAt: number;
+	lastLoginAt: number;
 }

 export interface ApiKey {
-  id: number;
-  userId: number;
-  prefix: string;
-  label: string;
-  scope: AccessLevel;
-  createdAt: number;
-  lastUsedAt: number;
-  expiresAt?: number;
+	id: number;
+	userId: number;
+	prefix: string;
+	label: string;
+	scope: AccessLevel;
+	createdAt: number;
+	lastUsedAt: number;
+	expiresAt?: number;
 }

 // ApiKeyCreated is the one-time response from POST /apikeys: the plaintext key
 // is shown exactly once and never retrievable again.
 export interface ApiKeyCreated {
-  id: number;
-  userId: number;
-  label: string;
-  scope: AccessLevel;
-  prefix: string;
-  createdAt: number;
-  key: string;
+	id: number;
+	userId: number;
+	label: string;
+	scope: AccessLevel;
+	prefix: string;
+	createdAt: number;
+	key: string;
 }

 export interface CanvasExportEnvelope {
-  _type: 'webui4frpc-canvas';
-  version: number;
-  exportedAt: number;
-  exporter: string;
-  canvas: CanvasData;
+	_type: "webui4frpc-canvas";
+	version: number;
+	exportedAt: number;
+	exporter: string;
+	canvas: CanvasData;
 }

 // Worker-log bundle (GET /cluster/logs/export): one entry per alive ring node.
 export interface WorkerLogEntry {
-  name: string;
-  remote: string;
-  state: string;
-  lines: string;
+	name: string;
+	remote: string;
+	state: string;
+	lines: string;
 }
 export interface NodeLogsResp {
-  node: string;
-  workers: WorkerLogEntry[];
+	node: string;
+	workers: WorkerLogEntry[];
 }
 export interface ClusterWorkerLogNode {
-  id: string;
-  addr: string;
-  ok: boolean;
-  error?: string;
-  logs?: NodeLogsResp;
+	id: string;
+	addr: string;
+	ok: boolean;
+	error?: string;
+	logs?: NodeLogsResp;
 }
 export interface WorkerLogBundle {
-  _type: 'webui4frpc-worker-logs';
-  version: number;
-  exportedAt: number;
-  requester: string;
-  nodes: ClusterWorkerLogNode[];
+	_type: "webui4frpc-worker-logs";
+	version: number;
+	exportedAt: number;
+	requester: string;
+	nodes: ClusterWorkerLogNode[];
 }
--- a/web/src/views/ClusterView.vue
+++ b/web/src/views/ClusterView.vue
@ -121,6 +121,131 @@
        </div>
      </section>

+      <!-- Load balancer (read-only). Shown only when the endpoint responds: a
+           404 means this node has no balancer wired up, and an absent section is
+           the honest signal for "this build doesn't do balancing". -->
+      <section class="section w4f-card bal-section" v-if="bal">
+        <h3 class="section-title">
+          <span class="k-ic">⚖</span>负载均衡
+          <!-- The switch edits the mode ON THIS NODE. Every member decides about
+               its own forwards, so a cluster-wide toggle would be a lie: there is
+               no single action that flips them together. -->
+          <el-select
+            v-if="bal.canControl"
+            v-model="balModeChoice"
+            size="small"
+            class="bal-mode"
+            :disabled="modeBusy"
+            @change="onModeChange"
+          >
+            <el-option label="关闭" value="off" />
+            <el-option label="观察模式（不释放）" value="dry-run" />
+            <el-option label="启用（会释放）" value="on" />
+          </el-select>
+          <span class="w4f-tag" v-else v-text="'只读'" ></span>
+          <span class="bal-src" v-if="bal.modeSource === 'stored'">已保存</span>
+          <span class="bal-src" v-else>来自启动参数</span>
+          <span class="w4f-tag" v-if="!bal.isMember" v-text="'非集群成员'"></span>
+          <span class="w4f-tag" v-else-if="bal.releasing" v-text="'释放进行中'"></span>
+          <span class="w4f-tag w4f-tag-warn" v-else-if="bal.selfOverShare" v-text="'本机超出份额'"></span>
+          <span class="w4f-tag w4f-tag-ok" v-else v-text="'本机在份额内'"></span>
+          <span class="title-actions">
+            <button class="w4f-btn ghost small" :disabled="busy" @click="load">⟳ 刷新</button>
+          </span>
+        </h3>
+
+        <div class="bal-thresholds">
+          <span>
+            规则：本机转发 <b>{{ bal.selfForwards }}</b> 条
+            &gt; 平摊份额 <b>{{ bal.share }}</b>
+            且至少 {{ 2 }} 条时，本机自行释放一条
+          </span>
+          <span>集群共 {{ bal.totalForwards }} 条 / {{ bal.aliveNodes }} 台存活</span>
+          <span>两次释放间隔 ≥ {{ Math.round(bal.cooldownSec / 60) }} 分钟</span>
+          <span v-if="bal.dryRun" class="bal-hint">
+            设 <code>W4F_BALANCE_MODE=on</code> 才会真正释放
+          </span>
+        </div>
+
+        <p class="bal-note">
+          每个节点各自判断自己的转发，超了就自己撤销一条并丢回环上，
+          由环节点按「最闲者优先」重新认领。没有中心调度。
+        </p>
+
+        <!-- Per-node forward counts. Bars are scaled to the busiest node so the
+             shape reads whether the cluster holds 3 forwards or 300; the share
+             marker is what actually decides, not the bar. -->
+        <div class="bal-nodes">
+          <div
+            v-for="n in balNodes"
+            :key="n.id"
+            class="bal-node"
+            :class="{ self: n.id === bal.self, over: n.forwards > bal.share }"
+          >
+            <div class="bn-top">
+              <span class="bn-id">{{ shortId(n.id) }}</span>
+              <span v-if="n.id === bal.self" class="w4f-tag w4f-tag-primary">本机</span>
+              <span v-if="n.isLeader" class="w4f-tag w4f-tag-info">LEADER</span>
+              <span v-if="!n.alive" class="w4f-tag w4f-tag-danger">离线</span>
+              <span v-if="n.alive && n.forwards > bal.share" class="w4f-tag w4f-tag-warn">超出份额</span>
+            </div>
+            <div class="w4f-bar" :class="{ err: n.alive && n.forwards > bal.share }">
+              <i :style="{ width: barWidth(n.forwards) + '%' }" />
+            </div>
+            <div class="bn-stats">
+              <span>转发 <b>{{ n.forwards }}</b></span>
+              <span>内存 <b>{{ n.memPct.toFixed(1) }}%</b></span>
+              <span>网络 <b>{{ n.netPct.toFixed(1) }}%</b></span>
+              <span class="bn-score">份额 <b>{{ bal.share }}</b></span>
+            </div>
+          </div>
+          <div v-if="!balNodes.length" class="empty">暂无节点负载数据</div>
+        </div>
+
+        <!-- What THIS node would do. The answer is per-node by design: every
+             member runs the same rule on its own forwards, so there is no
+             cluster-wide plan and no "the leader will move X to Y". -->
+        <div class="bal-plan">
+          <div v-if="bal.releasing" class="bp-inflight">
+            <span class="w4f-tag w4f-tag-warn">释放进行中</span>
+            <span class="bp-text">
+              本机已释放 {{ bal.releasing.local }}:{{ bal.releasing.remotePort }}，
+              等待环把它认领到别的节点
+            </span>
+          </div>
+          <div v-else-if="bal.wouldRelease && !bal.blockedBy" class="bp-would">
+            <span class="w4f-tag w4f-tag-warn">将释放</span>
+            <span class="bp-text">
+              本机将撤销 {{ bal.wouldRelease.local }}:{{ bal.wouldRelease.remotePort }}
+              并丢回环上，由最闲节点接管
+            </span>
+          </div>
+          <div v-else-if="bal.wouldRelease && bal.blockedBy === 'cooldown'" class="bp-waiting">
+            <span class="w4f-tag w4f-tag-info">冷却中</span>
+            <span class="bp-text">
+              本机超出份额，但距上次释放不足
+              {{ Math.round(bal.cooldownSec / 60) }} 分钟
+              <template v-if="bal.lastReleaseAt">
+                （已过 {{ cooldownAgo }}）
+              </template>
+            </span>
+          </div>
+          <div v-else-if="bal.wouldRelease" class="bp-waiting">
+            <span class="w4f-tag w4f-tag-info">暂不释放</span>
+            <span class="bp-text">本机超出份额，原因：{{ blockedLabel }}</span>
+          </div>
+          <div v-else-if="!bal.isMember" class="bp-ok">
+            <span class="w4f-tag w4f-tag-ok">单节点</span>
+            <span class="bp-text">本机未加入集群，无需均衡</span>
+          </div>
+          <div v-else class="bp-ok">
+            <span class="w4f-tag w4f-tag-ok">已均衡</span>
+            <span class="bp-text">
+              本机持有 {{ bal.selfForwards }} 条，未超平摊份额 {{ bal.share }}，无需释放
+            </span>
+          </div>
+        </div>
+      </section>
      <!-- Active forward topology -->
      <section class="section w4f-card">
        <h3 class="section-title"><span class="k-ic">→</span>活跃转发拓扑</h3>
@ -199,14 +324,18 @@
 </template>

 <script setup lang="ts">
-import { ref, reactive, computed, onMounted, onBeforeUnmount } from 'vue'
+import { ref, reactive, computed, onMounted, onBeforeUnmount, watch } from 'vue'
 import { ElMessage } from 'element-plus'
 import { api, downloadAuditCsv } from '../api'
 import { canWrite } from '../auth'
-import type { RingSnapshot, RingTaskInfo, RingLogEntry } from '../types'
+import type { BalanceReport, RingSnapshot, RingTaskInfo, RingLogEntry } from '../types'

 const ring = ref<RingSnapshot | null>(null)
 const busy = ref(false)
+// bal is null when the node has no balancer wired up (endpoint 404s). The
+// section is simply not rendered then, which is the honest signal for "this
+// build does not do balancing" — better than an empty panel implying it does.
+const bal = ref<BalanceReport | null>(null)
 let timer: number | null = null
 let visHandler: (() => void) | null = null

@ -214,8 +343,76 @@ const joinDialog = reactive({ visible: false, addr: '', key: '' })

 const load = async () => {
  try { ring.value = await api.ring() } catch { /* keep last */ }
+  // Loaded alongside the ring, but unlike it a failure clears the view: the
+  // balancer report is a decision surface, and showing a stale "已均衡" after the
+  // endpoint starts failing would be worse than showing nothing.
+  try { bal.value = await api.balance() } catch { bal.value = null }
 }

+// ---- load balancer mode switch ---- //
+// The select is bound to a local mirror so the UI can show the pending choice
+// while the request is in flight, and snap back if the server rejects it.
+const balModeChoice = ref<string>('dry-run')
+const modeBusy = ref(false)
+watch(
+  () => bal.value?.mode,
+  (m) => { if (m) balModeChoice.value = m },
+  { immediate: true },
+)
+const onModeChange = async (m: string) => {
+  if (!bal.value || modeBusy.value) return
+  modeBusy.value = true
+  try {
+    bal.value = await api.setBalanceMode(m)
+    ElMessage.success(
+      m === 'on' ? '本机已启用负载释放' : m === 'off' ? '本机已关闭负载均衡' : '本机已切到观察模式',
+    )
+  } catch (e) {
+    // Snap back: leaving the select showing a mode the server did not accept
+    // would misrepresent what the node is doing.
+    balModeChoice.value = bal.value.mode
+    ElMessage.error('切换失败：' + (e instanceof Error ? e.message : String(e)))
+  } finally {
+    modeBusy.value = false
+  }
+}
+
+// ---- load balancer view ---- //
+// Each node decides about its OWN forwards, so this page has no cluster-wide
+// plan to show — only what THIS node holds and what it is about to do.
+// Ordered by descending count: the busiest node first is what an operator
+// scanning for a hotspot wants.
+const balNodes = computed(() => [...(bal.value?.nodes ?? [])].sort((a, b) => b.forwards - a.forwards))
+// barWidth scales against the busiest node rather than an absolute, so the shape
+// is readable whether the cluster holds 3 forwards or 300. The bar is context;
+// `share` is what actually decides whether a node is over.
+const barWidth = (forwards: number) => {
+  const max = Math.max(...(bal.value?.nodes ?? []).map((n) => n.forwards), 1)
+  return Math.min(100, Math.round((forwards / max) * 100))
+}
+// blockedLabel renders the server's machine reason as something readable. The
+// reason matters: "over its share but not acting" is otherwise indistinguishable
+// from "broken".
+const blockedLabel = computed(() => {
+  switch (bal.value?.blockedBy) {
+    case 'cooldown': return '冷却期未过'
+    case 'in-flight': return '上一次释放尚未确认'
+    case 'nothing-active': return '本机可释放的转发都已停用'
+    case 'below-min': return '持有量低于下限'
+    case 'single-node': return '单节点环'
+    default: return bal.value?.blockedBy || '未说明'
+  }
+})
+// cooldownAgo says how long ago the last release was, so an operator can see
+// whether the cooldown is about to expire.
+const cooldownAgo = computed(() => {
+  const t = bal.value?.lastReleaseAt ?? 0
+  if (!t) return ''
+  const s = Math.max(0, Math.floor(nowMs.value / 1000) - t)
+  if (s < 60) return s + ' 秒前'
+  return Math.floor(s / 60) + ' 分钟前'
+})
+
 const shortId = (id: string) => (id.length > 22 ? '…' + id.slice(-20) : id)

 // copyNodeKey copies this node's admission key to the clipboard so the operator
@ -260,6 +457,8 @@ const stateDotClass = computed(() => {

 // ---- last-sync freshness (ops cares "环还活着吗", not the cycle counter) ----
 const now = ref(Date.now())
+// nowMs mirrors `now` as a plain number for the balance section's minute math.
+const nowMs = computed(() => now.value)
 let tick: number | null = null
 const lastSyncAgo = computed(() => {
  const ls = ring.value?.lastSync ?? 0
@ -638,4 +837,66 @@ onBeforeUnmount(() => {
  .kpis { grid-template-columns: minmax(0, 1fr); }
  .page-title { font-size: 15.5px; }
 }
+
+/* ---- Load balancer section ---- */
+.bal-section .section-title { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
+.bal-section .section-title .k-ic { margin-right: 0; }
+
+.bal-thresholds {
+  display: flex; flex-wrap: wrap; gap: 6px 14px;
+  font-size: 11.5px; color: var(--w4f-muted);
+  margin-bottom: 10px;
+}
+.bal-hint { color: var(--w4f-warning); }
+.bal-hint code {
+  font-family: var(--w4f-mono, ui-monospace, monospace);
+  background: var(--w4f-card-2); padding: 1px 4px; border-radius: 3px;
+}
+
+.bal-nodes {
+  display: grid; gap: 8px;
+  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
+}
+.bal-node {
+  border: 1px solid var(--w4f-line);
+  border-radius: 8px;
+  padding: 9px 11px;
+  background: var(--w4f-card-2);
+  min-width: 0;
+}
+.bal-node.self { border-color: var(--w4f-primary); }
+.bal-node.over { border-color: var(--w4f-warning); }
+.bal-mode { width: 168px; }
+.bal-src { font-size: 11px; color: var(--w4f-muted); }
+.bal-note {
+  margin: 0 0 10px; font-size: 11.5px; line-height: 1.55;
+  color: var(--w4f-muted);
+}
+.bn-top { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; margin-bottom: 7px; }
+.bn-id {
+  font-family: var(--w4f-mono, ui-monospace, monospace);
+  font-size: 12px; font-weight: 700;
+  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
+}
+.bn-stats {
+  display: flex; flex-wrap: wrap; gap: 3px 12px;
+  font-size: 11.5px; color: var(--w4f-muted); margin-top: 7px;
+}
+.bn-stats b { color: var(--w4f-text); font-variant-numeric: tabular-nums; }
+.bn-score { margin-left: auto; }
+
+.bal-plan { margin-top: 11px; }
+.bp-inflight, .bp-would, .bp-waiting, .bp-ok {
+  display: flex; align-items: center; gap: 9px; flex-wrap: wrap;
+  padding: 8px 11px; border-radius: 8px;
+  font-size: 12.5px;
+  background: var(--w4f-card-2);
+  border: 1px solid var(--w4f-line);
+}
+.bp-inflight { border-color: var(--w4f-warning); }
+.bp-text { min-width: 0; overflow-wrap: anywhere; }
+
+@media (max-width: 380px) {
+  .bn-score { margin-left: 0; }
+}
 </style>
--- a/web/src/views/StatusView.vue
+++ b/web/src/views/StatusView.vue
@ -187,6 +187,10 @@
        <label>Token</label>
        <el-input v-model="dialog.remote.token" :disabled="!canWrite" placeholder="可选" />
      </div>
+      <div class="form-row">
+        <label>user</label>
+        <el-input v-model="dialog.remote.user" :disabled="!canWrite" placeholder="面板型 frps 必填，普通 frps 可留空" />
+      </div>
      <div class="form-row">
        <label>URL</label>
        <el-input v-model="dialog.remote.url" :disabled="!canWrite" placeholder="可选" />
@ -226,6 +230,7 @@ const newRemote = (): Remote => ({
  port: 7000,
  token: '',
  url: '',
+  user: '',
  enabled: true,
 })

@ -246,7 +251,7 @@ const openEdit = (p: { name: string }) => {
  dialog.isNew = false
  dialog.remote = found
    ? { ...found }
-    : { name: p.name, ip: '', port: 7000, token: '', url: '', enabled: true }
+    : { name: p.name, ip: '', port: 7000, token: '', url: '', user: '', enabled: true }
  dialog.visible = true
 }