Add l2_server to UserContext

Fixes AttributeError when running recipes - the UserContext was
missing the l2_server field that run_service expects.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/services/auth_service.py

@@ -27,6 +27,7 @@ class UserContext:
     username: str
     actor_id: str
     token: Optional[str] = None
+    l2_server: Optional[str] = None
 
 
 class AuthService:
@@ -108,6 +109,7 @@ class AuthService:
             username=username,
             actor_id=actor_id or f"@{username}",
             token=token,
+            l2_server=settings.l2_server,
         )
 
     async def verify_token_with_l2(self, token: str) -> Optional[UserContext]: