fix: 注册 PUT /api/manager/settings 使设置保存生效

server.go NewServeMux 按方法分发到 handleSettingsPut（原仅注册 GET，PUT 静默返回旧值）

新增 TestSettingsPutRoundTrip 回归测试；gofmt 清理历史格式问题

internal/httpapi/server.go

@@ -61,7 +61,13 @@ func NewServeMux(h *Handler) (http.Handler, error) {
 	// API routes (basic auth).
 	mux.HandleFunc(apiPrefix+"/status", auth(h.handleStatus))
 	mux.HandleFunc(apiPrefix+"/canvas", auth(h.handleCanvasSave))
-	mux.HandleFunc(apiPrefix+"/settings", auth(h.handleSettingsGet))
+	mux.HandleFunc(apiPrefix+"/settings", auth(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method == http.MethodPut {
+			h.handleSettingsPut(w, r)
+			return
+		}
+		h.handleSettingsGet(w, r)
+	}))
 	mux.HandleFunc(apiPrefix+"/binary/status", auth(h.handleBinaryStatus))
 	mux.HandleFunc(apiPrefix+"/binary/install", auth(h.handleBinaryInstall))
 
@@ -135,10 +141,10 @@ func (h *Handler) handleStatus(w http.ResponseWriter, r *http.Request) {
 	settings, _ := h.Store.Settings()
 
 	type profileStatus struct {
-		Name     string         `json:"name"`
-		Enabled  bool           `json:"enabled"`
-		Status   process.Status `json:"process"`
-		HasProc  bool           `json:"hasProcess"`
+		Name     string          `json:"name"`
+		Enabled  bool            `json:"enabled"`
+		Status   process.Status  `json:"process"`
+		HasProc  bool            `json:"hasProcess"`
 		Forwards []store.Forward `json:"forwards"`
 	}
 
@@ -155,7 +161,7 @@ func (h *Handler) handleStatus(w http.ResponseWriter, r *http.Request) {
 		})
 	}
 
-		// Local status: each local plus its forwarding targets and whether each
+	// Local status: each local plus its forwarding targets and whether each
 	// target's worker is healthy (running).
 	type localTargetStatus struct {
 		Remote      string `json:"remote"`
@@ -163,8 +169,8 @@ func (h *Handler) handleStatus(w http.ResponseWriter, r *http.Request) {
 		WorkerState string `json:"workerState"`
 	}
 	type localStatus struct {
-		Local   store.Local          `json:"local"`
-		Targets []localTargetStatus  `json:"targets"`
+		Local   store.Local         `json:"local"`
+		Targets []localTargetStatus `json:"targets"`
 	}
 
 	localStatuses := make([]localStatus, 0, len(locals))
@@ -186,13 +192,13 @@ func (h *Handler) handleStatus(w http.ResponseWriter, r *http.Request) {
 	}
 
 	resp := map[string]any{
-		"version":    "0.1.0",
-		"workDir":    h.WorkDir,
-		"settings":   settings,
-		"services":   locals,
-		"remotes":    remotes,
-		"binaryPath": binary,
-		"profiles":   profiles,
+		"version":     "0.1.0",
+		"workDir":     h.WorkDir,
+		"settings":    settings,
+		"services":    locals,
+		"remotes":     remotes,
+		"binaryPath":  binary,
+		"profiles":    profiles,
 		"localStatus": localStatuses,
 	}
 	writeJSON(w, http.StatusOK, resp)