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/app.ts

@@ -4,7 +4,7 @@ import { createPinia } from 'pinia'
 // Core plugin system
 import { pluginManager } from './core/plugin-manager'
 import { eventBus } from './core/event-bus'
-import { container, SERVICE_TOKENS } from './core/di-container'
+import { container } from './core/di-container'
 
 // App configuration
 import appConfig from './app.config'