fix(logic): isolate atomic batch counters and token sync fields

tests/test_account_token_sync_status.py

@@ -0,0 +1,72 @@
+from src.database import crud
+from src.database.session import DatabaseSessionManager
+
+
+def test_create_account_marks_token_sync_pending_when_tokens_persist(tmp_path):
+    manager = DatabaseSessionManager(f"sqlite:///{tmp_path}/test.db")
+    manager.create_tables()
+    manager.migrate_tables()
+
+    with manager.session_scope() as session:
+        account = crud.create_account(
+            session,
+            email="sync@example.com",
+            email_service="tempmail",
+            access_token="access-token",
+            refresh_token="refresh-token",
+        )
+
+        assert account.token_sync_status == "pending"
+        assert account.token_sync_updated_at is not None
+
+
+def test_update_account_marks_token_sync_pending_when_tokens_change(tmp_path):
+    manager = DatabaseSessionManager(f"sqlite:///{tmp_path}/test.db")
+    manager.create_tables()
+    manager.migrate_tables()
+
+    with manager.session_scope() as session:
+        account = crud.create_account(
+            session,
+            email="nosync@example.com",
+            email_service="tempmail",
+        )
+
+        assert account.token_sync_status == "not_ready"
+
+        updated = crud.update_account(
+            session,
+            account.id,
+            access_token="new-access-token",
+        )
+
+        assert updated is not None
+        assert updated.token_sync_status == "pending"
+        assert updated.token_sync_updated_at is not None
+
+
+def test_update_account_preserves_pending_status_when_other_tokens_remain(tmp_path):
+    manager = DatabaseSessionManager(f"sqlite:///{tmp_path}/test.db")
+    manager.create_tables()
+    manager.migrate_tables()
+
+    with manager.session_scope() as session:
+        account = crud.create_account(
+            session,
+            email="partial-sync@example.com",
+            email_service="tempmail",
+            access_token="access-token",
+            refresh_token="refresh-token",
+        )
+
+        updated = crud.update_account(
+            session,
+            account.id,
+            refresh_token="",
+        )
+
+        assert updated is not None
+        assert updated.access_token == "access-token"
+        assert updated.refresh_token == ""
+        assert updated.token_sync_status == "pending"
+        assert updated.token_sync_updated_at is not None