feat: update video cut and extract head image job

backend/database/fields/medias.go

@@ -0,0 +1,7 @@
+package fields
+
+type MediaMetas struct {
+	ParentHash string `json:"parent_hash,omitempty"`
+	Short      bool   `json:"short,omitempty"`
+	Duration   int64  `json:"duration,omitempty"`
+}