Refactor imports and remove legacy composables for improved code clarity

- Simplify imports in app.ts by removing unused SERVICE_TOKENS.
- Eliminate the NavigationItem interface in Navbar.vue as its functionality is now managed by useModularNavigation.
- Introduce new legacy composable stubs for useNostrChat and useRelayHub, indicating a shift towards modular chat and relay services.
- Update MyTicketsPage.vue to correct the import path for useUserTickets, enhancing module organization.
- Refactor ChatService to improve type handling for event tags, ensuring better type safety.

Remove ChatComponent, useNostrChat composable, and ChatPage for a modular chat architecture

- Delete ChatComponent.vue to streamline chat functionality.
- Remove legacy useNostrChat composable, transitioning to a more modular chat service approach.
- Eliminate ChatPage.vue as part of the refactor to enhance code organization and maintainability.

src/composables/useRelayHub.ts

@@ -0,0 +1,7 @@
+// Legacy composable stub - replaced by modular base module services
+export function useRelayHub() {
+  return {
+    connectedRelays: [],
+    status: 'disconnected'
+  }
+}