feat(plugin hook): add client.subscribe.unavailable hook

app/Http/Controllers/V1/Client/ClientController.php

@@ -44,7 +44,18 @@ class ClientController extends Controller
         $userService = new UserService();
 
         if (!$userService->isAvailable($user)) {
-            return response()->json(['message' => 'Account unavailable'], 403);
+            HookManager::call('client.subscribe.unavailable');
+            return response('', 200, ['Content-Type' => 'text/plain']);
+        }
+
+        return $this->doSubscribe($request, $user);
+    }
+
+    public function doSubscribe(Request $request, $user, $servers = null)
+    {
+        if ($servers === null) {
+            $servers = ServerService::getAvailableServers($user);
+            $servers = HookManager::filter('client.subscribe.servers', $servers, $user, $request);
         }
 
         $clientInfo = $this->getClientInfo($request);
@@ -55,9 +66,6 @@ class ClientController extends Controller
         $protocolClassName = app('protocols.manager')->matchProtocolClassName($clientInfo['flag'])
             ?? General::class;
 
-        $servers = ServerService::getAvailableServers($user);
-        $servers = HookManager::filter('client.subscribe.servers', $servers, $user, $request);
-
         $serversFiltered = $this->filterServers(
             servers: $servers,
             allowedTypes: $requestedTypes,