story: DGR-041 Register native Shard capabilities without redesigning Meshnet

packages/node/meshnet_node/native_worker_supervisor.py

@@ -220,6 +220,23 @@ class NativeWorkerSupervisor:
             self._on_available("worker ready and identity verified")
         return result
 
+    def add_availability_callbacks(
+        self,
+        *,
+        on_available: AvailabilityCallback | None = None,
+        on_unavailable: AvailabilityCallback | None = None,
+    ) -> None:
+        """Attach an integration callback before the worker is started.
+
+        Registration is deliberately supplied by the caller so this supervisor
+        stays independent of Tracker HTTP and of every other backend.
+        """
+        with self._lock:
+            if self._process is not None:
+                raise NativeWorkerError("availability callbacks must be attached before start")
+            self._on_available = _combine_callbacks(self._on_available, on_available)
+            self._on_unavailable = _combine_callbacks(self._on_unavailable, on_unavailable)
+
     def restart(self) -> NativeWorkerProbe:
         """Withdraw the old capability, stop its process, then prove a fresh one."""
         self.stop(reason="worker restart requested")
@@ -330,6 +347,21 @@ def _sha256_file(path: Path) -> str:
     return digest.hexdigest()
 
 
+def _combine_callbacks(
+    first: AvailabilityCallback | None, second: AvailabilityCallback | None
+) -> AvailabilityCallback | None:
+    if first is None:
+        return second
+    if second is None:
+        return first
+
+    def combined(reason: str) -> None:
+        first(reason)
+        second(reason)
+
+    return combined
+
+
 def _terminate_process_group(
     process: subprocess.Popen[str], shutdown_timeout: float, kill_timeout: float
 ) -> None: