fix: 兼容像素分辨率参数

apps/api/internal/runner/param_processor_utils.go

@@ -29,7 +29,7 @@ func validateAndAdjustAspectRatio(aspectRatio string, capability map[string]any,
 	if containsString(allowed, aspectRatio) {
 		return aspectRatio, true
 	}
-	return allowed[0], true
+	return closestAspectRatio(aspectRatio, allowed), true
 }
 
 func isMediaModelTypeWithAspectRatio(capability map[string]any) bool {
@@ -445,6 +445,33 @@ func adjustAspectRatioToRange(value string, minValue float64, maxValue float64,
 	return ratioString(maxValue)
 }
 
+func closestAspectRatio(value string, allowed []string) string {
+	if len(allowed) == 0 {
+		return value
+	}
+	current, ok := aspectRatioNumber(value)
+	if !ok {
+		return allowed[0]
+	}
+	closest := ""
+	minDiff := math.Inf(1)
+	for _, candidate := range allowed {
+		ratio, ok := aspectRatioNumber(candidate)
+		if !ok {
+			continue
+		}
+		diff := math.Abs(ratio - current)
+		if diff < minDiff {
+			minDiff = diff
+			closest = candidate
+		}
+	}
+	if closest != "" {
+		return closest
+	}
+	return allowed[0]
+}
+
 func ratioString(value float64) string {
 	if value <= 0 {
 		return "1:1"