feat(gateway): 补齐桌面端高级媒体直连接口

新增图片矢量化、视频超分、每日用量、计价与任务隔离能力，并通过环境变量解析平台凭据。

已通过 Go 全量门禁、迁移检查、镜像构建以及 Vectorizer 五格式和 Topaz 3 秒视频真实 DEV 验收。

apps/api/internal/store/postgres.go

@@ -29,7 +29,7 @@ const (
 )
 
 func defaultAPIKeyScopes() []string {
-	return []string{"chat", "embedding", "rerank", "image", "video", "music", "audio", "voice_clone"}
+	return []string{"chat", "embedding", "rerank", "image", "image_vectorize", "video", "video_enhance", "music", "audio", "voice_clone"}
 }
 
 func normalizeAPIKeyScopes(scopes []string) []string {
@@ -517,7 +517,7 @@ type GatewayTask struct {
 	Message             string         `json:"message,omitempty"`
 	AttemptCount        int            `json:"attemptCount"`
 	RemoteTaskID        string         `json:"remoteTaskId,omitempty"`
-	RemoteTaskPayload   map[string]any `json:"remoteTaskPayload,omitempty"`
+	RemoteTaskPayload   map[string]any `json:"-"`
 	Result              map[string]any `json:"result,omitempty"`
 	Billings            []any          `json:"billings,omitempty"`
 	Usage               map[string]any `json:"usage"`