完善生图5.0的功能

backend/internal/providers/providers_test.go

@@ -666,6 +666,31 @@ func TestSeedreamPayloadAndSynchronousResponse(t *testing.T) {
 	}
 }
 
+func TestSeedreamLayerDecompositionPayloadAndResponseMetadata(t *testing.T) {
+	client := roundTripFunc(func(request *http.Request) (*http.Response, error) {
+		var body map[string]any
+		if err := json.NewDecoder(request.Body).Decode(&body); err != nil {
+			t.Fatal(err)
+		}
+		if body["image"] != "https://in.test/source.png" || body["layer_decomposition"] != true || body["prompt"] != nil || body["optimize_prompt_options"] != nil {
+			t.Fatalf("body=%#v", body)
+		}
+		return &http.Response{StatusCode: http.StatusOK, Body: io.NopCloser(strings.NewReader(`{
+			"data":[
+				{"url":"https://cdn.test/base.jpeg","size":"2048x2048","z_index":0},
+				{"url":"https://cdn.test/title.png","size":"500x100","z_index":1,"name":"标题"}
+			]
+		}`)), Header: http.Header{}}, nil
+	})
+	result, err := NewSeedream(Config{BaseURL: "https://ark.test/api/v3", APIKey: "secret", Model: Seedream50ProModel}, client).Submit(context.Background(), Request{
+		Capability: "image.generate", InputURLs: []string{"https://in.test/source.png"},
+		Settings: map[string]any{"size": "2K", "outputFormat": "jpeg", "layerDecomposition": true},
+	})
+	if err != nil || result.Status != StatusSucceeded || !reflect.DeepEqual(result.OutputURLs, []string{"https://cdn.test/base.jpeg", "https://cdn.test/title.png"}) || !strings.Contains(string(result.Raw), `"z_index":1`) {
+		t.Fatalf("result=%#v err=%v", result, err)
+	}
+}
+
 func TestMockIsDeterministic(t *testing.T) {
 	m := NewMock("fixture")
 	a, _ := m.Submit(context.Background(), Request{Capability: "video.generate", Prompt: "hello"})

backend/internal/providers/seedream.go

@@ -26,14 +26,21 @@ func NewSeedream(c Config, client HTTPClient) *Seedream {
 		payload: func(r Request) any {
 			payload := map[string]any{
 				"model":           requestModel(r, c.Model),
-				"prompt":          r.Prompt,
 				"size":            seedreamSetting(r.Settings, "size", "1.5K"),
 				"output_format":   seedreamSetting(r.Settings, "outputFormat", "png"),
 				"response_format": "url",
 				"watermark":       false,
-				"optimize_prompt_options": map[string]any{
+			}
+			if prompt := strings.TrimSpace(r.Prompt); prompt != "" {
+				payload["prompt"] = prompt
+			}
+			layerDecomposition, _ := r.Settings["layerDecomposition"].(bool)
+			if layerDecomposition {
+				payload["layer_decomposition"] = true
+			} else {
+				payload["optimize_prompt_options"] = map[string]any{
 					"mode": seedreamSetting(r.Settings, "optimizeMode", "standard"),
-				},
+				}
 			}
 			switch len(r.InputURLs) {
 			case 0: