feat(companion): expose pending request observability

src/companion/runtimeClient.test.ts

@@ -593,6 +593,44 @@ describe('CompanionRuntimeClient', () => {
     );
   });
 
+  it('tracks pendingRequestCount for in-flight RPCs', async () => {
+    class FakeWebSocket extends EventEmitter {
+      readyState: number = WebSocket.CONNECTING;
+
+      constructor() {
+        super();
+        queueMicrotask(() => {
+          this.readyState = WebSocket.OPEN;
+          this.emit('open');
+        });
+      }
+
+      send(_payload: string, callback?: (error?: Error) => void): void {
+        callback?.();
+      }
+
+      close(_code?: number, _reason?: string): void {
+        this.readyState = WebSocket.CLOSED;
+        this.emit('close');
+      }
+    }
+
+    const client = new CompanionRuntimeClient({
+      url: 'ws://127.0.0.1:1',
+      websocketFactory: () => new FakeWebSocket() as unknown as WebSocket,
+      requestTimeoutMs: 10_000,
+    });
+    await client.connect();
+    expect(client.pendingRequestCount).toBe(0);
+
+    const pending = client.call('system.capabilities');
+    expect(client.pendingRequestCount).toBe(1);
+
+    client.disconnect();
+    await expect(pending).rejects.toThrow('Disconnected');
+    expect(client.pendingRequestCount).toBe(0);
+  });
+
   it('connects and performs node registration + capability discovery', async () => {
     if (!LISTEN_ALLOWED) {
       return;