fix(event): prefer real session.idle over recent synthetic dedup (#2667)

The dedup logic dropped real session.idle events when a synthetic
idle had fired within the dedup window, losing data that downstream
hooks needed. Now real idle events always reach dispatchToHooks while
synthetic duplicates are still dropped when a real event came first.

🤖 Generated with OhMyOpenCode assistance
https://github.com/code-yeongyu/oh-my-opencode

src/plugin/event.ts

@@ -323,7 +323,6 @@ export function createEventHandler(args: {
         const emittedAt = recentSyntheticIdles.get(sessionID);
         if (emittedAt && Date.now() - emittedAt < DEDUP_WINDOW_MS) {
           recentSyntheticIdles.delete(sessionID);
-          return;
         }
         recentRealIdles.set(sessionID, Date.now());
       }