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

ts/sipproxy.ts

@@ -273,15 +273,23 @@ async function startProxyEngine(): Promise<void> {
       legs: new Map(),
     });
 
-    // Notify browsers of incoming call.
-    const browserIds = getAllBrowserDeviceIds();
-    for (const bid of browserIds) {
-      sendToBrowserDevice(bid, {
-        type: 'webrtc-incoming',
-        callId: data.call_id,
-        from: data.from_uri,
-        deviceId: bid,
-      });
+    // Notify browsers of the incoming call, but only if the matched inbound
+    // route asked for it. `ring_browsers !== false` preserves today's
+    // ring-by-default behavior for any Rust release that predates this
+    // field or for the fallback "no route matched" case (where Rust still
+    // sends `true`). Note: this is an informational toast — browsers do
+    // NOT race the SIP device to answer. First-to-answer-wins requires
+    // a multi-leg fork which is not yet implemented.
+    if (data.ring_browsers !== false) {
+      const browserIds = getAllBrowserDeviceIds();
+      for (const bid of browserIds) {
+        sendToBrowserDevice(bid, {
+          type: 'webrtc-incoming',
+          callId: data.call_id,
+          from: data.from_uri,
+          deviceId: bid,
+        });
+      }
     }
   });