The SSE query subscription error handler only checked for subCode-based
errors (EVENT_STREAM_DOES_NOT_EXIST, EVENT_STREAM_ALREADY_EXISTS) but
the "Schema version mismatch" and "App version mismatch" errors from
the server don't include a subCode extension. This caused them to fall
through to the default case which threw an unhandled error to Sentry.
Handle these version mismatch errors gracefully by resetting active
query listeners and destroying the event stream, allowing it to be
recreated after the user refreshes.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>