fix: exclude admin/system users from all third-party API tasks

Catalog, VK catalog, and VK sync tasks were querying all connections
regardless of user role. Admin and system accounts with stored tokens
were generating unnecessary Evotor and VK API calls. Now all three
tasks join to the users table and filter role = 'user' only.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/tasks/vk_sync.py

@@ -20,6 +20,7 @@ from web.models.connections import (
     SyncConfig, SyncFilter,
     VkCachedAlbum, VkConnection,
 )
+from web.models.user import User, UserRoleEnum
 
 logger = logging.getLogger(__name__)
 
@@ -412,12 +413,14 @@ def mirror_to_vk(self) -> dict:
     try:
         vk_connections = (
             db.query(VkConnection)
+            .join(User, User.id == VkConnection.user_id)
             .filter(
                 VkConnection.user_id.isnot(None),
                 VkConnection.access_token.isnot(None),
                 VkConnection.access_token != "",
                 VkConnection.vk_user_id.isnot(None),
                 VkConnection.vk_user_id != "",
+                User.role == UserRoleEnum.user,
             )
             .all()
         )