fix(config): 将前端访问开关限制为仅控制首页

移除用户前端开关对订阅入口、用户 API 与访客接口的拦截，
关闭 `frontend_enable` 时仅让用户首页 `/` 返回空 404。

同时更新后台配置文案、测试用例与模块文档，明确 API、
订阅和节点接口保持原有访问边界。

app/Http/Routes/V1/ClientRoute.php

@@ -11,7 +11,7 @@ class ClientRoute
     {
         $router->group([
             'prefix' => 'client',
-            'middleware' => ['user.frontend', 'client']
+            'middleware' => 'client'
         ], function ($router) {
             // Client
             $router->get('/subscribe', [ClientController::class, 'subscribe'])->name('client.subscribe.legacy');

app/Http/Routes/V1/GuestRoute.php

@@ -14,18 +14,14 @@ class GuestRoute
         $router->group([
             'prefix' => 'guest'
         ], function ($router) {
-            $router->group([
-                'middleware' => 'user.frontend'
-            ], function ($router) {
-                // Plan
-                $router->get('/plan/fetch', [PlanController::class, 'fetch']);
-                // Comm
-                $router->get('/comm/config', [CommController::class, 'config']);
-            });
+            // Plan
+            $router->get('/plan/fetch', [PlanController::class, 'fetch']);
             // Telegram
             $router->post('/telegram/webhook', [TelegramController::class, 'webhook']);
             // Payment
             $router->match(['get', 'post'], '/payment/notify/{method}/{uuid}', [PaymentController::class, 'notify']);
+            // Comm
+            $router->get('/comm/config', [CommController::class, 'config']);
         });
     }
 }

app/Http/Routes/V1/PassportRoute.php

@@ -10,8 +10,7 @@ class PassportRoute
     public function map(Registrar $router)
     {
         $router->group([
-            'prefix' => 'passport',
-            'middleware' => 'user.frontend'
+            'prefix' => 'passport'
         ], function ($router) {
             // Auth
             $router->post('/auth/register', [AuthController::class, 'register']);

app/Http/Routes/V1/UserRoute.php

@@ -22,7 +22,7 @@ class UserRoute
     {
         $router->group([
             'prefix' => 'user',
-            'middleware' => ['user.frontend', 'user']
+            'middleware' => 'user'
         ], function ($router) {
             // User
             $router->get('/resetSecurity', [UserController::class, 'resetSecurity']);