feat: unify native API invocation with async callbacks (#1476)

pkg/rest/invoke.go

@@ -13,10 +13,13 @@ const (
 	TaskEventError = uint64(goapi.TaskEventError)
 )
 
-// Invoke dispatches a Core API request without using an HTTP listener. It is
-// the shared entry point for Desktop FFI and gomobile bindings.
-func Invoke(method, path, rawQuery, body string) string {
+// Dispatch executes one in-process API request. Native scheduling and callback
+// behavior belong to bind/native; this function only bridges into the shared
+// API Service without opening an HTTP listener.
+func Dispatch(method, path, rawQuery, body string) string {
+	runtimeMu.RLock()
 	service := APIService
+	runtimeMu.RUnlock()
 	if service == nil {
 		return marshalInvokeResult(model.NewErrorResult("service not started"))
 	}
@@ -29,6 +32,8 @@ func Invoke(method, path, rawQuery, body string) string {
 }
 
 func SubscribeTaskEvents(mask uint64, listener func(payload string)) {
+	runtimeMu.RLock()
+	defer runtimeMu.RUnlock()
 	if APIService == nil {
 		return
 	}