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/pages/ChatPage.vue

@@ -1,22 +0,0 @@
-<template>
-  <div class="container mx-auto p-4 h-[calc(100vh-3.5rem-2rem)] lg:h-[calc(100vh-4rem-2rem)] xl:h-[calc(100vh-5rem-2rem)]">
-    <div class="flex flex-col h-full">
-      <!-- Page Header -->
-      <div class="mb-4">
-        <h1 class="text-2xl font-bold">Nostr Chat</h1>
-        <p class="text-muted-foreground">
-          Chat with other LNBits users using Nostr relays
-        </p>
-      </div>
-
-      <!-- Chat Component -->
-      <div class="flex-1 border rounded-lg overflow-hidden">
-        <ChatComponent />
-      </div>
-    </div>
-  </div>
-</template>
-
-<script setup lang="ts">
-import ChatComponent from '@/components/nostr/ChatComponent.vue'
-</script>