feat: Integrate Relay Hub for centralized Nostr connection management

- Introduce a new composable, useRelayHub, to manage all Nostr WebSocket connections, enhancing connection stability and performance.
- Update existing components and composables to utilize the Relay Hub for connecting, publishing events, and subscribing to updates, streamlining the overall architecture.
- Add a RelayHubStatus component to display connection status and health metrics, improving user feedback on the connection state.
- Implement a RelayHubDemo page to showcase the functionality of the Relay Hub, including connection tests and subscription management.
- Ensure proper error handling and logging throughout the integration process to facilitate debugging and user experience.

src/stores/nostr.ts

@@ -1,6 +1,6 @@
 import { defineStore } from 'pinia'
 import { ref } from 'vue'
-import { NostrClient } from '@/lib/nostr/client'
+import { relayHub } from '@/lib/nostr/relayHub'
 import { config } from '@/lib/config'
 import { pushService, type PushSubscriptionData } from '@/lib/notifications/push'
 
@@ -23,17 +23,6 @@ export const useNostrStore = defineStore('nostr', () => {
   // Push notifications
   const pushSubscription = ref<PushSubscriptionData | null>(null)
   const notificationsEnabled = ref(false)
-  
-  // Singleton client instance
-  let client: NostrClient | null = null
-
-  // Get or create client instance
-  function getClient(): NostrClient {
-    if (!client) {
-      client = new NostrClient({ relays: relayUrls.value })
-    }
-    return client
-  }
 
   // Connection management
   async function connect(): Promise<void> {
@@ -41,10 +30,11 @@ export const useNostrStore = defineStore('nostr', () => {
       error.value = null
       isConnecting.value = true
       
-      const nostrClient = getClient()
-      await nostrClient.connect()
+      // Initialize and connect using the centralized relay hub
+      await relayHub.initialize(relayUrls.value)
+      await relayHub.connect()
       
-      isConnected.value = nostrClient.isConnected
+      isConnected.value = relayHub.isConnected
     } catch (err) {
       error.value = err instanceof Error ? err : new Error('Failed to connect')
       isConnected.value = false
@@ -55,10 +45,8 @@ export const useNostrStore = defineStore('nostr', () => {
   }
 
   function disconnect(): void {
-    if (client) {
-      client.disconnect()
-      client = null
-    }
+    // Don't disconnect the relay hub as it's managed centrally
+    // Just update our local state
     isConnected.value = false
     isConnecting.value = false
     error.value = null
@@ -71,11 +59,7 @@ export const useNostrStore = defineStore('nostr', () => {
 
   function setRelayUrls(urls: string[]) {
     relayUrls.value = urls
-    // Recreate client with new relays
-    if (client) {
-      client.disconnect()
-      client = null
-    }
+    // The relay hub will handle reconnection with new relays if needed
   }
 
   function setAccount(nostrAccount: NostrAccount | null) {
@@ -111,7 +95,6 @@ export const useNostrStore = defineStore('nostr', () => {
       localStorage.removeItem('notifications-enabled')
     } catch (error) {
       console.error('Failed to disable push notifications:', error)
-      throw error
     }
   }
 
@@ -154,6 +137,33 @@ export const useNostrStore = defineStore('nostr', () => {
     })
   }
 
+  // Setup relay hub event listeners to keep store state in sync
+  function setupRelayHubListeners(): void {
+    relayHub.on('connected', () => {
+      isConnected.value = true
+      isConnecting.value = false
+      error.value = null
+    })
+
+    relayHub.on('disconnected', () => {
+      isConnected.value = false
+      isConnecting.value = false
+    })
+
+    relayHub.on('error', (err: Error) => {
+      error.value = err
+      isConnected.value = false
+      isConnecting.value = false
+    })
+
+    relayHub.on('connecting', () => {
+      isConnecting.value = true
+    })
+  }
+
+  // Initialize relay hub listeners
+  setupRelayHubListeners()
+
   return {
     // State
     isConnected,
@@ -167,7 +177,6 @@ export const useNostrStore = defineStore('nostr', () => {
     // Actions
     connect,
     disconnect,
-    getClient,
     setConnected,
     setRelayUrls,
     setAccount,