1、后台界面/video-engines，添加修改需要增加可传图片和视频的数量

2、前台接口/credits/ratios，同步返回

video-gen-api/app/schemas/video_engine.py

@@ -13,6 +13,8 @@ class VideoEngineCreate(BaseModel):
     supported_resolutions: str = Field(default='["480p","720p","1080p"]')
     supported_durations: str = Field(default='[4,5,6,7,8,9,10,11,12,13,14,15]')
     max_duration: int = Field(default=15)
+    max_image_count: int = Field(default=5)
+    max_video_count: int = Field(default=2)
     generate_url: str = Field(default="", max_length=512)
     query_url: str = Field(default="", max_length=512)
     is_active: bool = True
@@ -33,6 +35,8 @@ class VideoEnginePublic(BaseModel):
     supported_ratios: list[str] = []
     supported_resolutions: list[str] = []
     supported_durations: list[int] = []
+    max_image_count: int = 5
+    max_video_count: int = 2
 
 
 class VideoEngineListResponse(BaseModel):