fix: grok-image 补齐 aspect_ratio 与 resolution 传参 (#184)

* fix: grok-image 补齐 aspect_ratio 与 resolution 传参

- 能力配置开放比例与 1k/2k 分辨率
- 请求体映射 size→aspect_ratio、quality→resolution
- 画布设置展示「分辨率」选项
- 补充单测

Closes #182

* fix(create): 创作页图片质量支持 1k/2k 分辨率选项

创作页原先硬编码 auto/low/medium/high，导致 grok 能力配置里的 1k/2k
无法显示；改为按模型 quality.values 动态渲染，有 1k/2k 时标题显示「分辨率」。

backend/internal/service/model_capability.go

@@ -109,8 +109,9 @@ func DefaultImageCapabilityConfig(protocol string, modelName string) *ImageCapab
 	case model.ChannelInterfaceGrokImage:
 		image.References.MaxImages = 1
 		image.References.MaskSupported = false
-		image.Size = ImageSizeConfig{Parameter: "none", Values: []string{}, Default: "auto", AllowCustom: false}
-		image.Quality = ImageQualityConfig{Supported: false, Values: []string{}, Default: "auto"}
+		// grok2api / xAI Imagine：size→aspect_ratio，quality→resolution(1k/2k)。
+		image.Size = ImageSizeConfig{Parameter: "aspect_ratio", Values: []string{"1:1", "3:4", "4:3", "9:16", "16:9", "2:3", "3:2"}, Default: "1:1", AllowCustom: false}
+		image.Quality = ImageQualityConfig{Supported: true, Values: []string{"1k", "2k"}, Default: "2k"}
 		image.TransparentBackground = VideoBooleanConfig{Supported: false, Default: false}
 		image.ResponseFormat = ParameterSupport{Supported: true}
 		image.OutputFormat = ParameterSupport{Supported: false}
@@ -132,8 +133,8 @@ func DefaultImageCapabilityConfig(protocol string, modelName string) *ImageCapab
 	if model.ChannelInterfaceType(protocol) != model.ChannelInterfaceGrokImage && strings.HasPrefix(strings.ToLower(strings.TrimSpace(modelName)), "grok-imagine-image") {
 		image.References.MaxImages = 0
 		image.References.MaskSupported = false
-		image.Size = ImageSizeConfig{Parameter: "none", Values: []string{}, Default: "auto", AllowCustom: false}
-		image.Quality = ImageQualityConfig{Supported: false, Values: []string{}, Default: "auto"}
+		image.Size = ImageSizeConfig{Parameter: "aspect_ratio", Values: []string{"1:1", "3:4", "4:3", "9:16", "16:9", "2:3", "3:2"}, Default: "1:1", AllowCustom: false}
+		image.Quality = ImageQualityConfig{Supported: true, Values: []string{"1k", "2k"}, Default: "2k"}
 		image.TransparentBackground = VideoBooleanConfig{Supported: false, Default: false}
 		image.ResponseFormat = ParameterSupport{Supported: true}
 		image.OutputFormat = ParameterSupport{Supported: false}

backend/internal/service/provider.go

@@ -746,7 +746,15 @@ func grokImageRequestBody(input canvasGenerationInput) (grokImageRequest, string
 	if input.Mask != nil {
 		return grokImageRequest{}, "", errors.New("Grok 图片协议不支持蒙版编辑，请移除蒙版后重试")
 	}
-	body := grokImageRequest{Model: input.Config.Model, Prompt: withSystemPrompt(input.Config, input.Prompt), N: 1, ResponseFormat: "url"}
+	body := grokImageRequest{
+		Model:          input.Config.Model,
+		Prompt:         withSystemPrompt(input.Config, input.Prompt),
+		N:              1,
+		ResponseFormat: "url",
+		Size:           strings.TrimSpace(input.Config.Size),
+		AspectRatio:    normalizeGrokImageAspectRatio(input.Config.Size),
+		Resolution:     normalizeGrokImageResolution(input.Config.Quality),
+	}
 	if len(input.ReferenceImages) == 0 {
 		return body, "/images/generations", nil
 	}
@@ -761,6 +769,63 @@ func grokImageRequestBody(input canvasGenerationInput) (grokImageRequest, string
 	return body, "/images/edits", nil
 }
 
+// normalizeGrokImageResolution 把画布 quality（1k/2k/high…）映射为 grok2api / xAI 的 resolution。
+func normalizeGrokImageResolution(quality string) string {
+	raw := strings.ToLower(strings.TrimSpace(quality))
+	switch raw {
+	case "", "auto":
+		return ""
+	case "1k", "low", "standard":
+		return "1k"
+	case "2k", "medium", "hd", "high", "4k":
+		// xAI Imagine 图片通常最高 2k；超出则夹到 2k，避免上游拒参。
+		return "2k"
+	default:
+		return ""
+	}
+}
+
+// normalizeGrokImageAspectRatio 把画布 size（如 1280x720 / 9:16）转成 grok2api / xAI 接受的 aspect_ratio。
+func normalizeGrokImageAspectRatio(size string) string {
+	raw := strings.ToLower(strings.TrimSpace(strings.ReplaceAll(size, "×", "x")))
+	if raw == "" || raw == "auto" {
+		return ""
+	}
+	if strings.Contains(raw, ":") {
+		switch raw {
+		case "1:1", "3:4", "4:3", "9:16", "16:9", "2:3", "3:2", "9:19.5", "19.5:9", "1:2", "2:1":
+			return raw
+		}
+	}
+	parts := strings.Split(raw, "x")
+	if len(parts) != 2 {
+		return ""
+	}
+	w, wErr := strconv.Atoi(parts[0])
+	h, hErr := strconv.Atoi(parts[1])
+	if wErr != nil || hErr != nil || w <= 0 || h <= 0 {
+		return ""
+	}
+	if w == h {
+		return "1:1"
+	}
+	ratio := float64(w) / float64(h)
+	switch {
+	case w*9 == h*16 || (ratio >= 1.7 && ratio <= 1.8):
+		return "16:9"
+	case h*9 == w*16 || (ratio > 0 && ratio <= 1.0/1.7 && ratio >= 1.0/1.8):
+		return "9:16"
+	case w*3 == h*4 || (ratio > 1.2 && ratio < 1.4):
+		return "4:3"
+	case h*3 == w*4 || (ratio > 0.7 && ratio < 0.85):
+		return "3:4"
+	case w > h:
+		return "16:9"
+	default:
+		return "9:16"
+	}
+}
+
 func grokImageInputURL(media providerMedia) (string, error) {
 	if isPublicMediaURL(strings.TrimSpace(media.URL)) {
 		return strings.TrimSpace(media.URL), nil

backend/internal/service/provider_request_types.go

@@ -58,6 +58,10 @@ type grokImageRequest struct {
 	Image          *grokImageInput `json:"image,omitempty"`
 	N              int             `json:"n"`
 	ResponseFormat string          `json:"response_format"`
+	Size           string          `json:"size,omitempty"`
+	AspectRatio    string          `json:"aspect_ratio,omitempty"`
+	// Resolution 对应 xAI / grok2api 的 resolution（常见 1k / 2k）。
+	Resolution string `json:"resolution,omitempty"`
 }
 
 type grokImageInput struct {

backend/internal/service/provider_test.go

@@ -196,6 +196,40 @@ func TestRunGrokImageTaskUsesJSONEditContract(t *testing.T) {
 	}
 }
 
+func TestGrokImageRequestBodyMapsAspectRatio(t *testing.T) {
+	body, path, err := grokImageRequestBody(canvasGenerationInput{
+		Prompt: "a cat",
+		Config: providerConfig{Model: "grok-imagine-image", InterfaceType: "grok-image", Size: "9:16", Quality: "2k"},
+	})
+	if err != nil {
+		t.Fatalf("grokImageRequestBody() error = %v", err)
+	}
+	if path != "/images/generations" {
+		t.Fatalf("path = %q", path)
+	}
+	if body.AspectRatio != "9:16" || body.Size != "9:16" || body.Resolution != "2k" {
+		t.Fatalf("body = %#v", body)
+	}
+	if got := normalizeGrokImageAspectRatio("1280x720"); got != "16:9" {
+		t.Fatalf("normalize 1280x720 = %q", got)
+	}
+	if got := normalizeGrokImageAspectRatio("720x1280"); got != "9:16" {
+		t.Fatalf("normalize 720x1280 = %q", got)
+	}
+}
+
+func TestNormalizeGrokImageResolution(t *testing.T) {
+	if got := normalizeGrokImageResolution("1k"); got != "1k" {
+		t.Fatalf("1k = %q", got)
+	}
+	if got := normalizeGrokImageResolution("high"); got != "2k" {
+		t.Fatalf("high = %q", got)
+	}
+	if got := normalizeGrokImageResolution("auto"); got != "" {
+		t.Fatalf("auto = %q", got)
+	}
+}
+
 func TestGrokImageRequestBodyRejectsMaskAndMultipleReferences(t *testing.T) {
 	if _, _, err := grokImageRequestBody(canvasGenerationInput{Config: providerConfig{InterfaceType: "grok-image"}, Mask: &providerMedia{DataURL: testReferenceImageDataURL}}); err == nil || !strings.Contains(err.Error(), "不支持蒙版") {
 		t.Fatalf("mask error = %v", err)