feat(voice): dynamic settings voice picker with safe fallback + preview (#690)

* feat(voice): dynamic settings voice picker with safe fallback + preview

* fix(voice): honor picker with configured agent and stop preview on unmount

* fix(voice): apply PR review feedback for agent selection and preview cleanup

web/src/api/client.ts

@@ -538,7 +538,7 @@ export class ApiClient {
         })
     }
 
-    async fetchVoiceToken(options?: { customAgentId?: string; customApiKey?: string }): Promise<{
+    async fetchVoiceToken(options?: { customAgentId?: string; customApiKey?: string; voiceId?: string }): Promise<{
         allowed: boolean
         token?: string
         agentId?: string
@@ -549,4 +549,22 @@ export class ApiClient {
             body: JSON.stringify(options || {})
         })
     }
+
+    async fetchVoices(): Promise<{ voices: Array<{ id: string; name: string; previewUrl: string; category: string }> }> {
+        return await this.request('/api/voice/voices')
+    }
+
+    async sendVoiceTelemetry(event: {
+        stage: string
+        message: string
+        sessionId?: string
+        voiceId?: string
+        language?: string
+        details?: Record<string, unknown>
+    }): Promise<void> {
+        await this.request('/api/voice/telemetry', {
+            method: 'POST',
+            body: JSON.stringify(event)
+        })
+    }
 }