feat: support multi-image image generation

apps/api/serializers.py

@@ -35,6 +35,7 @@ class GenerateImageRequestSerializer(serializers.Serializer):
     )
     image_url = serializers.URLField(required=False, allow_blank=True)
     image_base64 = serializers.CharField(required=False, allow_blank=True)
+    images = serializers.ListField(required=False, write_only=True)
     resolution = serializers.CharField(
         required=False,
         allow_blank=True,
@@ -49,8 +50,29 @@ class GenerateImageRequestSerializer(serializers.Serializer):
     )
     parameters = serializers.DictField(required=False, default=dict)
 
+    def validate_images(self, value):
+        if not value:
+            raise serializers.ValidationError("images 至少需要一张图片。")
+        max_images = max(1, int(settings.IMAGE_MAX_INPUT_IMAGES))
+        if len(value) > max_images:
+            raise serializers.ValidationError(f"单次最多上传 {max_images} 张图片。")
 
-class VisionImageInputSerializer(serializers.Serializer):
+        serializer = ImageInputSerializer(data=value, many=True)
+        serializer.is_valid(raise_exception=True)
+        return serializer.validated_data
+
+    def validate(self, attrs):
+        has_legacy_image = bool(str(attrs.get("image_url") or "").strip()) or bool(
+            str(attrs.get("image_base64") or "").strip()
+        )
+        if attrs.get("images") is not None and has_legacy_image:
+            raise serializers.ValidationError(
+                "images 不能与 image_url 或 image_base64 同时提供。"
+            )
+        return attrs
+
+
+class ImageInputSerializer(serializers.Serializer):
     image_url = serializers.URLField(required=False, allow_blank=True)
     image_base64 = serializers.CharField(required=False, allow_blank=True)
 
@@ -64,6 +86,10 @@ class VisionImageInputSerializer(serializers.Serializer):
         return attrs
 
 
+class VisionImageInputSerializer(ImageInputSerializer):
+    pass
+
+
 class AnalyzeImagesRequestSerializer(serializers.Serializer):
     prompt = serializers.CharField(trim_whitespace=True, allow_blank=False)
     model = serializers.CharField(