fix: warn and skip invalid event handlers

* Initial plan

* Add warning log with file path for missing event handler function

Co-authored-by: twlite <46562212+twlite@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: twlite <46562212+twlite@users.noreply.github.com>

Author: Copilot

packages/commandkit/src/app/handlers/AppEventsHandler.ts

@@ -106,7 +106,8 @@ export class AppEventsHandler {
         const handler = await import(toFileURL(listener, true));
 
         if (!handler.default || typeof handler.default !== 'function') {
-          Logger.error`Event handler for ${event.event}${event.namespace ? ` of namespace ${event.namespace}` : ''} does not have a default export or is not a function`;
+          Logger.warn`Event handler for ${event.event}${event.namespace ? ` of namespace ${event.namespace}` : ''} at "${listener}" does not have a default export or is not a function. Skipping...`;
+          continue;
         }
 
         listeners.push({