G3.1: dedicated bridge heartbeat — watchdog liveness independent of audio loop

native_bridge/src/main.cpp

@@ -657,6 +657,17 @@ int main(int argc, char* argv[]) {
     if (!shmIPC) return 1;
 #endif
 
+    // G3.1: dedicated heartbeat thread, independent of the audio loop.
+    // Increments every 100ms (~10Hz). Tauri watchdog keys liveness on this.
+    // Started right after the SHM map so a slow instrument restore at
+    // startup (or after watchdog respawn) never looks like a dead bridge.
+    std::thread([shmIPC]() {
+        for (;;) {
+            Sleep(100);
+            shmIPC->heartbeat++;
+        }
+    }).detach();
+
     InstrumentEngineManager instruments;
 #ifdef _WIN32
     g_engine = &instruments;