fix(server-activity): ignore writes for deleted users

server/app/db_operations/activity.py

@@ -4,6 +4,7 @@
 from uuid import UUID
 from fastapi import HTTPException, Request
 import jwt
+from sqlalchemy.exc import IntegrityError
 from sqlmodel import Session, select
 from app.db_operations.token import ALGORITHM, SECRET_KEY
 from app.models.activity import UserActivity
@@ -48,6 +49,8 @@ def _write_user_activity_sync(user_id: UUID, ip: str, user_agent: str) -> None:
             activity.ip_address = ip
             session.add(activity)
             session.commit()
+    except IntegrityError:
+        pass
     except Exception as e:
         print(f"[activity] write failed: {e}")
 

server/app/tests/test_activity.py

@@ -1,7 +1,12 @@
 """Regression coverage for concurrent user-presence updates."""
 from uuid import uuid4
 
-from app.db_operations.activity import _get_user_activity_for_update
+from sqlalchemy.exc import IntegrityError
+
+from app.db_operations.activity import (
+    _get_user_activity_for_update,
+    _write_user_activity_sync,
+)
 
 
 class _Result:
@@ -24,3 +29,29 @@ def test_presence_lookup_locks_the_user_activity_row():
 
     assert _get_user_activity_for_update(session, uuid4()) is None
     assert session.statement._for_update_arg is not None
+
+
+def test_activity_write_ignores_missing_user_foreign_key(monkeypatch, capsys):
+    class FailingSession:
+        def __enter__(self):
+            return self
+
+        def __exit__(self, *_):
+            return False
+
+        def exec(self, _):
+            return _Result()
+
+        def add(self, _):
+            pass
+
+        def commit(self):
+            raise IntegrityError("INSERT", {}, Exception("foreign key constraint"))
+
+    monkeypatch.setattr(
+        "app.db_operations.activity.Session", lambda _: FailingSession()
+    )
+
+    _write_user_activity_sync(uuid4(), "127.0.0.1", "pytest")
+
+    assert capsys.readouterr().out == ""