Add container restart/stop/start controls

- Add HandleAppRestart, HandleAppStop, HandleAppStart handlers
- Wire up POST routes for /apps/{id}/restart, /stop, /start
- Use helper function to reduce code duplication

internal/handlers/app.go

@@ -380,6 +380,89 @@ func (h *Handlers) HandleAppLogs() http.HandlerFunc {
 	}
 }
 
+// containerAction represents a container operation type.
+type containerAction string
+
+const (
+	actionRestart containerAction = "restart"
+	actionStop    containerAction = "stop"
+	actionStart   containerAction = "start"
+)
+
+// handleContainerAction is a helper for container control operations.
+func (h *Handlers) handleContainerAction(
+	writer http.ResponseWriter,
+	request *http.Request,
+	action containerAction,
+) {
+	appID := chi.URLParam(request, "id")
+
+	application, findErr := models.FindApp(request.Context(), h.db, appID)
+	if findErr != nil || application == nil {
+		http.NotFound(writer, request)
+
+		return
+	}
+
+	if !application.ContainerID.Valid {
+		http.Redirect(writer, request, "/apps/"+appID, http.StatusSeeOther)
+
+		return
+	}
+
+	containerID := application.ContainerID.String
+	ctx := request.Context()
+
+	var actionErr error
+
+	switch action {
+	case actionRestart:
+		stopErr := h.docker.StopContainer(ctx, containerID)
+		if stopErr != nil {
+			h.log.Error("failed to stop container for restart",
+				"error", stopErr, "app", application.Name, "container", containerID)
+		}
+
+		actionErr = h.docker.StartContainer(ctx, containerID)
+	case actionStop:
+		actionErr = h.docker.StopContainer(ctx, containerID)
+	case actionStart:
+		actionErr = h.docker.StartContainer(ctx, containerID)
+	}
+
+	if actionErr != nil {
+		h.log.Error("container action failed",
+			"action", action, "error", actionErr,
+			"app", application.Name, "container", containerID)
+	} else {
+		h.log.Info("container action completed",
+			"action", action, "app", application.Name, "container", containerID)
+	}
+
+	http.Redirect(writer, request, "/apps/"+appID, http.StatusSeeOther)
+}
+
+// HandleAppRestart handles restarting an app's container.
+func (h *Handlers) HandleAppRestart() http.HandlerFunc {
+	return func(writer http.ResponseWriter, request *http.Request) {
+		h.handleContainerAction(writer, request, actionRestart)
+	}
+}
+
+// HandleAppStop handles stopping an app's container.
+func (h *Handlers) HandleAppStop() http.HandlerFunc {
+	return func(writer http.ResponseWriter, request *http.Request) {
+		h.handleContainerAction(writer, request, actionStop)
+	}
+}
+
+// HandleAppStart handles starting an app's container.
+func (h *Handlers) HandleAppStart() http.HandlerFunc {
+	return func(writer http.ResponseWriter, request *http.Request) {
+		h.handleContainerAction(writer, request, actionStart)
+	}
+}
+
 // addKeyValueToApp is a helper for adding key-value pairs (env vars or labels).
 func (h *Handlers) addKeyValueToApp(
 	writer http.ResponseWriter,

internal/server/routes.go

@@ -64,6 +64,9 @@ func (s *Server) SetupRoutes() {
 		r.Post("/apps/{id}/deploy", s.handlers.HandleAppDeploy())
 		r.Get("/apps/{id}/deployments", s.handlers.HandleAppDeployments())
 		r.Get("/apps/{id}/logs", s.handlers.HandleAppLogs())
+		r.Post("/apps/{id}/restart", s.handlers.HandleAppRestart())
+		r.Post("/apps/{id}/stop", s.handlers.HandleAppStop())
+		r.Post("/apps/{id}/start", s.handlers.HandleAppStart())
 
 		// Environment variables
 		r.Post("/apps/{id}/env-vars", s.handlers.HandleEnvVarAdd())