fix(apps/demo): clarify connect?.() comment — Driver.connect() is optional in interface

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>
Agent-Logs-Url: https://github.com/objectstack-ai/objectql/sessions/b2684b8f-f82b-4586-af12-a917a8f44471

Author: Copilot

apps/demo/objectstack.config.ts

@@ -89,7 +89,7 @@ export default {
                 ctx.registerService('driver.default', defaultDriver);
             },
             start: async () => {
-                // Both MemoryDriver and TursoDriver implement connect()
+                // Driver.connect() is optional in the interface; call if present
                 await defaultDriver.connect?.();
             },
         },