fix(video): 异步任务 - 完善全局轮询容错与调度策略

backend/internal/app/protocol_runtime_test.go

@@ -13,6 +13,7 @@ import (
 	"regexp"
 	"strings"
 	"testing"
+	"time"
 
 	"infinite-canvas/backend/internal/protocol"
 )
@@ -348,6 +349,18 @@ func TestDeclarativeProtocolRuntimeExecutesCreatePollAndDownload(t *testing.T) {
 	}
 }
 
+func TestDeclarativeProtocolPollingPolicyOnlyChangesVideoBehavior(t *testing.T) {
+	video := declarativeProtocolPollPolicy("video")
+	if video.InitialDelay != defaultVideoPollInterval || !video.RetryTransient {
+		t.Fatalf("video polling policy = %#v, want delayed resilient polling", video)
+	}
+
+	image := declarativeProtocolPollPolicy("image")
+	if image.InitialDelay != 0 || image.Interval != 2500*time.Millisecond || image.RetryTransient {
+		t.Fatalf("image polling policy = %#v, want legacy immediate fail-fast polling", image)
+	}
+}
+
 func TestDeclarativeProtocolPollRecoversFromTransientGatewayFailure(t *testing.T) {
 	adapter, err := protocol.LoadManifest([]byte(`{
 		"apiVersion":"yingce.plugin/v1",