fix: update ElevenLabs SDK and fix voice AI WebSocket disconnect

- Upgrade @elevenlabs/react 0.14.1 → 0.14.3
- Upgrade @elevenlabs/client 0.15.0 → 0.15.2

Root cause: ElevenLabs server now sends 'multimodal_message' WebSocket
events during session init. The old client (0.15.0) didn't handle this
event type — the server would close the connection, then the SDK cleanup
called socket.close() on an already-CLOSED socket, producing the repeated
"WebSocket is already in CLOSING or CLOSED state" errors.

0.15.2 adds multimodal_message handling, restoring the connection flow.

Also fixed: overrides.agent.first_message (snake_case) → firstMessage
(camelCase) — SDK reads i.firstMessage so the greeting was silently
dropped on every call start.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: amethystani

package-lock.json

@@ -13,7 +13,8 @@
   "dependencies": {
     "@11labs/client": "^0.0.4",
     "@base-ui/react": "^1.2.0",
-    "@elevenlabs/react": "^0.14.1",
+    "@elevenlabs/client": "^0.15.2",
+    "@elevenlabs/react": "^0.14.3",
     "@radix-ui/react-accordion": "^1.2.12",
     "@radix-ui/react-dialog": "^1.1.15",
     "@radix-ui/react-separator": "^1.1.8",

package.json

@@ -144,7 +144,8 @@ export default function UserPhoneInterface({
                             prompt: systemPrompt,
                         },
                         // Use the KB greeting as the agent's opening line
-                        first_message: knowledgeBase.greeting || undefined,
+                        // SDK reads firstMessage (camelCase), not first_message
+                        firstMessage: knowledgeBase.greeting || undefined,
                     },
                 },
             });