perf: 회원가입 쿼리 최적화 (268개 → 58개, 78% 감소)

- MenuObserver: Bulk insert + 지연 캐시 삭제로 메뉴당 28개 → 3개 쿼리
- RegisterService: 중복 권한 생성 로직 제거 (27개 쿼리 감소)
- 캐시 삭제: 126개 → 11개 (91% 감소)
- 확장성 유지: 관리자 메뉴 추가 시에도 최적화 적용

app/Services/RegisterService.php

@@ -85,21 +85,21 @@ public static function register(array $params): array
                 'description' => '시스템 관리자',
             ]);
 
-            // 8. Create permissions for each menu and assign to role
-            $permissions = [];
+            // 8. Get all permissions created by MenuObserver (menu:{id}.{action} pattern)
+            $permissionNames = [];
+            $actions = config('authz.menu_actions', ['view', 'create', 'update', 'delete', 'approve']);
+
             foreach ($menuIds as $menuId) {
-                $permName = "menu.{$menuId}";
-
-                // Use firstOrCreate to avoid duplicate permission errors
-                $perm = Permission::firstOrCreate([
-                    'tenant_id' => $tenant->id,
-                    'guard_name' => 'api',
-                    'name' => $permName,
-                ]);
-
-                $permissions[] = $perm;
+                foreach ($actions as $action) {
+                    $permissionNames[] = "menu:{$menuId}.{$action}";
+                }
             }
 
+            $permissions = Permission::whereIn('name', $permissionNames)
+                ->where('tenant_id', $tenant->id)
+                ->where('guard_name', 'api')
+                ->get();
+
             // 9. Assign all menu permissions to system_manager role
             $role->syncPermissions($permissions);