feat(gateway): report provider lifecycle

gateway/control_plane.go

@@ -76,6 +76,15 @@ func (c *ControlPlaneClient) Release(ctx context.Context, authority protocol.Ses
 	return err
 }
 
+func (c *ControlPlaneClient) ReportProviderState(ctx context.Context, state protocol.ProviderState) error {
+	payload, err := protocol.EncodeProviderState(state)
+	if err != nil {
+		return err
+	}
+	_, err = c.post(ctx, "/api/v1/gateway/provider-state", payload)
+	return err
+}
+
 func (c *ControlPlaneClient) post(ctx context.Context, path string, payload []byte) ([]byte, error) {
 	if c == nil || c.HTTPClient == nil || c.BaseURL == "" {
 		return nil, errors.New("control-plane client is not configured")