feat(voice): add real-time voice room with LiveKit

- LiveKit WebRTC SFU container in docker-compose
- Voice token microservice (Node.js + Express)
- VoiceRoom page with member grid and controls
- useVoiceRoom composable for LiveKit connection
- Voice entry button in TeamSessionPanel
- Nginx proxy for voice-token service API

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/api/voice.ts

@@ -0,0 +1,31 @@
+// src/api/voice.ts
+import { pb } from './pocketbase'
+
+const LIVEKIT_URL = import.meta.env.VITE_LIVEKIT_URL || 'ws://192.168.1.14:7880'
+
+export function getLiveKitUrl(): string {
+  return LIVEKIT_URL
+}
+
+export async function fetchVoiceToken(sessionId: string): Promise<string> {
+  const user = pb.authStore.model
+  if (!user) throw new Error('未登录')
+
+  const token = pb.authStore.token
+
+  const res = await fetch(`/voice-api/voice-token/${sessionId}`, {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/json',
+      Authorization: token,
+    },
+  })
+
+  if (!res.ok) {
+    const data = await res.json().catch(() => ({ error: '语音服务暂不可用' }))
+    throw new Error(data.error || '语音服务暂不可用')
+  }
+
+  const data = await res.json()
+  return data.token
+}