feat: per-forward worker 模型 — 每条转发独立 frpc 配置+独立进程

核心改动（ring 协议不变，Task 本来就是 {Local,Remote,Link} 三元组）:
- process.WorkerKey: worker 键改为 'local~remote~port' 三元组
- renderForward: 每条 forward 渲染只含 1 个 proxy 的独立 frpc 配置
  (替代 renderRemote 把该 remote 全部 forwards 塞进一个进程)
- ClaimFn/RevokeFn: 认领/撤销只操作这一条 forward 自己的进程
- SyncWorkers/auto-start: 只拉起 localOnly 转发的独立进程,
  集群转发由 ring 认领节点拉起 (消除三台争抢 proxy already exists)
- RemoteStatus/StartRemote/StopRemote/RestartRemote: remote 级聚合辅助,
  保持 /profiles API 形状不变, 前端零改动
- handleStatus/logs: 按 worker key 解析真实 remote 名

效果: 三台节点的 frpc 各自只注册自己拥有的 proxy, 单条转发故障不再波及兄弟

internal/httpapi/handlers.go

@@ -2,11 +2,13 @@ package httpapi
 
 import (
 	"encoding/json"
+	"log"
 	"net/http"
 	"os"
 	"strings"
 
 	"webui4frpc/internal/cluster"
+	"webui4frpc/internal/process"
 	"webui4frpc/internal/store"
 )
 
@@ -127,8 +129,11 @@ func (h *Handler) applyCanvas(w http.ResponseWriter, r *http.Request, canvas *ca
 			if !keep[old.Name] {
 				if old.LocalOnly {
 					if h.Process != nil {
+						// Per-forward model: stop every localOnly worker of this local.
 						if fwd, _ := s.LinksForLocal(old.Name); len(fwd) > 0 {
-							_ = h.Process.Stop(fwd[0].Remote)
+							for _, f := range fwd {
+								_ = h.Process.Stop(process.WorkerKey(old.Name, f.Remote, f.RemotePort))
+							}
 						}
 					}
 				} else if h.Ring != nil {
@@ -324,9 +329,13 @@ func (h *Handler) handleRemoteUpsert(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
-	// Start the worker if enabled.
+	// Start the per-forward workers for this remote if enabled.
 	if rem.Enabled {
-		_ = h.Process.Start(rem.Name)
+		// In the per-forward model, merely upserting a remote does not start
+		// any workers — the actual links control which forwards run. The
+		// caller is expected to save the canvas (PUT /canvas) or start
+		// individual forwards via the forwards page.
+		log.Printf("remote %s upserted (enabled=%v); use status page forwards to start", rem.Name, rem.Enabled)
 	}
 	writeJSON(w, http.StatusOK, rem)
 }
@@ -341,7 +350,7 @@ func (h *Handler) handleRemoteDelete(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "remote name required", http.StatusBadRequest)
 		return
 	}
-	_ = h.Process.Stop(name)
+	_ = h.Process.StopRemote(name)
 	if err := h.Store.DeleteRemote(name); err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
@@ -367,8 +376,10 @@ func (h *Handler) handleProfile(w http.ResponseWriter, r *http.Request) {
 
 	switch action {
 	case "":
-		// GET profile status
-		st, has := h.Process.Status(name)
+		// GET profile status — aggregate per-forward workers into a single
+		// remote-centric view. "hasProcess" is true when ANY forward worker
+		// for this remote is running.
+		st, has := h.Process.RemoteStatus(name)
 		forwards, _ := h.Store.LinksForRemote(name)
 		writeJSON(w, http.StatusOK, map[string]any{
 			"name": name, "process": st, "hasProcess": has, "forwards": forwards,
@@ -384,11 +395,11 @@ func (h *Handler) handleProfile(w http.ResponseWriter, r *http.Request) {
 			}
 			var err error
 			if action == "start" {
-				err = h.Process.Start(name)
+				err = h.Process.StartRemote(name)
 			} else if action == "stop" {
-				err = h.Process.Stop(name)
+				err = h.Process.StopRemote(name)
 			} else {
-				err = h.Process.Restart(name)
+				err = h.Process.RestartRemote(name)
 			}
 			if err != nil {
 				http.Error(w, err.Error(), http.StatusInternalServerError)
@@ -399,7 +410,15 @@ func (h *Handler) handleProfile(w http.ResponseWriter, r *http.Request) {
 			methodNotAllowed(w)
 		}
 	case "config":
-		data, err := os.ReadFile(h.Process.ConfigPath(name))
+		// Per-forward model: no single config file for a remote. Return the
+		// first forward's config as a hint; the status page already shows
+		// per-forward configs.
+		workers := h.Process.RemoteWorkers(name)
+		if len(workers) == 0 {
+			http.NotFound(w, r)
+			return
+		}
+		data, err := os.ReadFile(h.Process.ConfigPath(workers[0]))
 		if err != nil {
 			http.NotFound(w, r)
 			return
@@ -407,7 +426,13 @@ func (h *Handler) handleProfile(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "application/json")
 		_, _ = w.Write(data)
 	case "logs":
-		path := h.Process.LogPath(name)
+		// Per-forward model: return the first per-forward log for this remote.
+		workers := h.Process.RemoteWorkers(name)
+		if len(workers) == 0 {
+			http.Error(w, "no workers for this remote", http.StatusNotFound)
+			return
+		}
+		path := h.Process.LogPath(workers[0])
 		data, err := tailFile(path, 64*1024)
 		if err != nil {
 			http.Error(w, err.Error(), http.StatusInternalServerError)