fix(migrations): preserve runtime logging during upgrades

alembic/env.py

@@ -20,7 +20,10 @@ database_url = config.attributes.get("database_url") or settings.database_url
 config.set_main_option("sqlalchemy.url", database_url)
 
 if config.config_file_name is not None:
-    fileConfig(config.config_file_name)
+    # Migrations can run inside the long-lived application process when module
+    # state changes. Do not let Alembic's logging setup disable loggers that the
+    # server already created (for example slow-request diagnostics).
+    fileConfig(config.config_file_name, disable_existing_loggers=False)
 
 
 def _target_metadata():