fix(proxy-engine): fix inbound route browser ringing and provider-facing SDP advertisement while preventing RTP port exhaustion

ts/proxybridge.ts

@@ -94,6 +94,11 @@ export interface IIncomingCallEvent {
   from_uri: string;
   to_number: string;
   provider_id: string;
+  /** Whether registered browsers should see a `webrtc-incoming` toast for
+   *  this call. Set by the Rust engine from the matched inbound route's
+   *  `ringBrowsers` flag (defaults to `true` when no route matches, so
+   *  deployments without explicit routes preserve pre-routing behavior). */
+  ring_browsers?: boolean;
 }
 
 export interface IOutboundCallEvent {