refactor(core): introduce EventBus and refactor store infrastructure

- Add EventBus for decoupled event-driven communication between services
- Add EventSubscriber component for centralized event handling
- Add requestDedupe utility for shared request deduplication
- Refactor api/wsService to use eventBus instead of direct router navigation
- Extract MessageMapper.toCachedMessages for consistent message mapping
- Remove deprecated BaseManager and CacheBus classes
- Improve @mention rendering with memberMap support in segment rendering
- Update hooks to use useRef instead of useState for fetch tracking

src/infrastructure/EventSubscriber.tsx

@@ -0,0 +1,44 @@
+import { useEffect } from 'react';
+import { router } from 'expo-router';
+import * as Haptics from 'expo-haptics';
+import { eventBus, AppEvent } from '@/core/events/EventBus';
+import { hrefVerificationGuide } from '@/navigation/hrefs';
+
+let verificationModalShown = false;
+
+export function EventSubscriber() {
+  useEffect(() => {
+    return eventBus.subscribe((event: AppEvent) => {
+      switch (event.type) {
+        case 'NAVIGATE':
+          router.push(event.payload.path);
+          break;
+
+        case 'NAVIGATE_BACK':
+          router.back();
+          break;
+
+        case 'SHOW_VERIFICATION_MODAL':
+          if (verificationModalShown) return;
+          verificationModalShown = true;
+          router.push(hrefVerificationGuide());
+          setTimeout(() => {
+            verificationModalShown = false;
+          }, 3000);
+          break;
+
+        case 'VIBRATE':
+          Haptics.notificationAsync(
+            event.payload.type === 'message'
+              ? Haptics.NotificationFeedbackType.Success
+              : event.payload.type === 'group_message'
+                ? Haptics.NotificationFeedbackType.Warning
+                : Haptics.NotificationFeedbackType.Error
+          ).catch(() => {});
+          break;
+      }
+    });
+  }, []);
+
+  return null;
+}