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/process/process.go

@@ -287,6 +287,88 @@ func (m *Manager) ListWorkers() []string {
 	return out
 }
 
+// RemoteWorkers returns the worker keys of all per-forward workers whose key
+// parses to the given remote name. In the per-forward model every link has
+// its own process keyed "local~remote~port"; this aggregates them so remote-
+// centric callers (status page, profile endpoints) can report an overall
+// view without knowing the key format.
+func (m *Manager) RemoteWorkers(remote string) []string {
+	var out []string
+	for _, key := range m.ListWorkers() {
+		if _, r, _, ok := ParseWorkerKey(key); ok && r == remote {
+			out = append(out, key)
+		}
+	}
+	return out
+}
+
+// RemoteStatus summarizes a remote's per-forward workers into one Status:
+// running when ANY forward worker runs; crashed/starting/restarting take
+// priority in that order; stopped (has=false) when no worker exists.
+// This keeps the legacy per-remote status shape working on top of the
+// per-forward worker model.
+func (m *Manager) RemoteStatus(remote string) (Status, bool) {
+	keys := m.RemoteWorkers(remote)
+	if len(keys) == 0 {
+		return Status{State: "stopped"}, false
+	}
+	summary := Status{State: "stopped"}
+	worst := -1 // rank: running=0 < others=1 < crashed=2
+	for _, k := range keys {
+		st, _ := m.Status(k)
+		rank := 1
+		switch st.State {
+		case "running":
+			rank = 0
+		case "crashed":
+			rank = 2
+		}
+		if rank > worst || (rank == worst && summary.State == "stopped") {
+			if rank != worst || st.State != "stopped" {
+				summary = st
+				worst = rank
+			}
+		}
+	}
+	return summary, true
+}
+
+// StartRemote starts every per-forward worker of one remote. Missing workers
+// are skipped; the first error wins.
+func (m *Manager) StartRemote(remote string) error {
+	var firstErr error
+	for _, key := range m.RemoteWorkers(remote) {
+		if err := m.Start(key); err != nil && firstErr == nil {
+			firstErr = err
+		}
+	}
+	return firstErr
+}
+
+// RestartRemote restarts every per-forward worker belonging to one remote
+// (used where the old model had a single per-remote worker). Missing workers
+// are skipped; the first error wins.
+func (m *Manager) RestartRemote(remote string) error {
+	var firstErr error
+	for _, key := range m.RemoteWorkers(remote) {
+		if err := m.Restart(key); err != nil && firstErr == nil {
+			firstErr = err
+		}
+	}
+	return firstErr
+}
+
+// StopRemote stops every per-forward worker of one remote.
+func (m *Manager) StopRemote(remote string) error {
+	var firstErr error
+	for _, key := range m.RemoteWorkers(remote) {
+		if err := m.Stop(key); err != nil && firstErr == nil {
+			firstErr = err
+		}
+	}
+	return firstErr
+}
+
 // StopAll stops all workers (used on manager shutdown).
 func (m *Manager) StopAll() {
 	m.mu.Lock()

internal/process/worker_key.go

@@ -0,0 +1,39 @@
+package process
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// WorkerKey is the unique identity of ONE forward's worker process:
+//
+//	"<local>~<remote>~<port>"
+//
+// The per-forward worker model gives every link its own frpc process, config
+// file and log file. This fixes the multi-node proxy-name fight of the old
+// per-remote model (every node rendered the SAME proxy list and raced to
+// register them on frps -> "proxy already exists"), and isolates faults: one
+// crashing forward can no longer take its siblings down.
+//
+// '~' is a legal filename character on every supported OS (including Windows,
+// unlike ':') and is rare in user-chosen node names. ParseWorkerKey rejects
+// malformed keys so callers fail loudly instead of silently mis-rendering.
+func WorkerKey(local, remote string, port int) string {
+	return fmt.Sprintf("%s~%s~%d", local, remote, port)
+}
+
+// ParseWorkerKey splits a worker key back into its (local, remote, port)
+// forward triple. ok=false for anything that is not a well-formed key
+// (e.g. legacy per-remote worker names).
+func ParseWorkerKey(key string) (local, remote string, port int, ok bool) {
+	parts := strings.Split(key, "~")
+	if len(parts) != 3 {
+		return "", "", 0, false
+	}
+	p, err := strconv.Atoi(parts[2])
+	if err != nil || parts[0] == "" || parts[1] == "" || p <= 0 {
+		return "", "", 0, false
+	}
+	return parts[0], parts[1], p, true
+}

internal/process/worker_key_test.go

@@ -0,0 +1,37 @@
+package process
+
+import "testing"
+
+func TestWorkerKeyRoundTrip(t *testing.T) {
+	cases := []struct {
+		local, remote string
+		port          int
+	}{
+		{"web", "frps1", 18080},
+		{"db", "aliyun-frps", 5432},
+		{"svc-1", "node.a.example", 80},
+	}
+	for _, c := range cases {
+		key := WorkerKey(c.local, c.remote, c.port)
+		l, r, p, ok := ParseWorkerKey(key)
+		if !ok || l != c.local || r != c.remote || p != c.port {
+			t.Fatalf("roundtrip %q -> (%q,%q,%d,%v)", key, l, r, p, ok)
+		}
+	}
+}
+
+func TestParseWorkerKeyRejectsBad(t *testing.T) {
+	bad := []string{
+		"", "srv-a", // legacy per-remote names / empty
+		"a~b",   // missing port
+		"a~b~x", // non-numeric port
+		"a~b~0", // port out of range
+		"~b~1",  // empty local
+		"a~~1",  // empty remote
+	}
+	for _, key := range bad {
+		if _, _, _, ok := ParseWorkerKey(key); ok {
+			t.Fatalf("ParseWorkerKey(%q) accepted, want reject", key)
+		}
+	}
+}