fix(security) : add role checks on Gitea API resources and all MCP tools

- GiteaBranch, GiteaBranchName, GiteaPullRequest: require ROLE_USER
- All 22 MCP tools: require ROLE_USER (ROLE_ADMIN for users/clients listing)

Tickets: T-002, T-007

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/Mcp/Tool/Task/ListTasksTool.php

@@ -7,12 +7,15 @@ namespace App\Mcp\Tool\Task;
 use App\Mcp\Tool\Serializer;
 use App\Repository\TaskRepository;
 use Mcp\Capability\Attribute\McpTool;
+use Symfony\Bundle\SecurityBundle\Security;
+use Symfony\Component\Security\Core\Exception\AccessDeniedException;
 
 #[McpTool(name: 'list-tasks', description: 'List tasks with optional filters by project, status, assignee, priority, group, tags, and archive state. Returns max 100 results by default, use filters to narrow down.')]
 class ListTasksTool
 {
     public function __construct(
         private readonly TaskRepository $taskRepository,
+        private readonly Security $security,
     ) {}
 
     public function __invoke(
@@ -25,6 +28,10 @@ class ListTasksTool
         bool $archived = false,
         int $limit = 100,
     ): string {
+        if (!$this->security->isGranted('ROLE_USER')) {
+            throw new AccessDeniedException('Access denied: ROLE_USER required.');
+        }
+
         $limit = min($limit, 200);
 
         $qb = $this->taskRepository->createQueryBuilder('t')