voice-call: fix docker-compose scope and constant placement

- Reset docker-compose.yml to main and apply only the intended change:
  commented-out voice webhook port with instructions for when to enable
- Move STREAM_TOKEN_TTL_MS above the class JSDoc where it belongs

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

extensions/voice-call/src/webhook/realtime-handler.ts

@@ -32,6 +32,7 @@ export type ToolHandlerFn = (args: unknown, callId: string) => Promise<unknown>;
  * handleWebSocketUpgrade + MediaStreamCallbacks) so the bridge and call-manager
  * wiring can be reused without duplicating the OpenAI session logic.
  */
+
 /** How long (ms) a stream token remains valid after TwiML is issued. */
 const STREAM_TOKEN_TTL_MS = 30_000;