fix(media): 规范比例与 OpenAI 图像尺寸参数

统一过滤非 x:x 比例，避免默认值参与候选匹配或透传上游。

支持 xK 分辨率归一化，并按 Gemini、Volces 和 OpenAI 的参数规范生成上游请求；OpenAI 显式 WxH 始终保留用户原始尺寸。

验证：在独立临时 worktree 中执行 apps/api 全量 go test ./... -count=1 通过，真实 OpenAI 请求已到达上游但受本地无效凭据阻断。

apps/api/internal/runner/param_processor_utils.go

@@ -393,23 +393,39 @@ func numberPair(value any) ([2]float64, bool) {
 }
 
 func validAspectRatio(value string) bool {
-	if value == "adaptive" || value == "keep_ratio" {
-		return true
-	}
-	_, ok := aspectRatioNumber(value)
+	_, ok := normalizedAspectRatio(value)
 	return ok
 }
 
-func aspectRatioNumber(value string) (float64, bool) {
-	parts := strings.Split(value, ":")
+func normalizedAspectRatio(value string) (string, bool) {
+	compact := strings.Map(func(r rune) rune {
+		switch r {
+		case ' ', '\t', '\r', '\n':
+			return -1
+		default:
+			return r
+		}
+	}, strings.TrimSpace(value))
+	parts := strings.Split(compact, ":")
 	if len(parts) != 2 {
-		return 0, false
+		return "", false
 	}
 	width := parsePositiveFloat(parts[0])
 	height := parsePositiveFloat(parts[1])
 	if width <= 0 || height <= 0 {
+		return "", false
+	}
+	return parts[0] + ":" + parts[1], true
+}
+
+func aspectRatioNumber(value string) (float64, bool) {
+	normalized, ok := normalizedAspectRatio(value)
+	if !ok {
 		return 0, false
 	}
+	parts := strings.Split(normalized, ":")
+	width := parsePositiveFloat(parts[0])
+	height := parsePositiveFloat(parts[1])
 	return width / height, true
 }
 
@@ -537,11 +553,53 @@ func isEmptyParamString(value string) bool {
 }
 
 func isImageResolution(modelType string, value string) bool {
-	return (modelType == "image_generate" || modelType == "image_edit") && containsString([]string{"1K", "2K", "3K", "4K", "8K"}, value)
+	if modelType != "image_generate" && modelType != "image_edit" {
+		return false
+	}
+	return normalizeImageResolution(value) != ""
 }
 
 func isVideoResolution(modelType string, value string) bool {
-	return isVideoModelType(modelType) && containsString([]string{"480p", "720p", "1080p", "1440p", "2160p"}, value)
+	return isVideoModelType(modelType) && normalizeVideoResolution(value) != ""
+}
+
+func normalizeMediaResolution(modelType string, value string) string {
+	if modelType == "image_generate" || modelType == "image_edit" {
+		return normalizeImageResolution(value)
+	}
+	if isVideoModelType(modelType) {
+		return normalizeVideoResolution(value)
+	}
+	return ""
+}
+
+func normalizeImageResolution(value string) string {
+	value = strings.ToLower(strings.TrimSpace(value))
+	if len(value) < 2 || value[len(value)-1] != 'k' {
+		return ""
+	}
+	magnitude, err := strconv.Atoi(value[:len(value)-1])
+	if err != nil || magnitude <= 0 {
+		return ""
+	}
+	return strconv.Itoa(magnitude) + "K"
+}
+
+func normalizeVideoResolution(value string) string {
+	switch strings.ToLower(strings.TrimSpace(value)) {
+	case "480p":
+		return "480p"
+	case "720p":
+		return "720p"
+	case "1080p":
+		return "1080p"
+	case "1440p":
+		return "1440p"
+	case "2160p", "4k":
+		return "2160p"
+	default:
+		return ""
+	}
 }
 
 func isVideoModelType(modelType string) bool {