feat: add boards and tasks management endpoints

backend/app/services/admin_access.py

@@ -0,0 +1,10 @@
+from __future__ import annotations
+
+from fastapi import HTTPException, status
+
+from app.core.auth import AuthContext
+
+
+def require_admin(auth: AuthContext) -> None:
+    if auth.actor_type != "user" or auth.user is None:
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN)