feat: sync initial schema migration

backend/database/models/media_assets.gen.go

@@ -34,7 +34,7 @@ type MediaAsset struct {
 	CreatedAt     time.Time                             `gorm:"column:created_at;type:timestamp with time zone;default:now()" json:"created_at"`
 	UpdatedAt     time.Time                             `gorm:"column:updated_at;type:timestamp with time zone;default:now()" json:"updated_at"`
 	DeletedAt     gorm.DeletedAt                        `gorm:"column:deleted_at;type:timestamp with time zone" json:"deleted_at"`
-	Hash          string                                `gorm:"column:hash;type:character varying(64);comment:File SHA-256 hash" json:"hash"` // File SHA-256 hash
+	Hash          string                                `gorm:"column:hash;type:character varying(64);comment:文件 MD5 哈希" json:"hash"` // 文件 MD5 哈希
 }
 
 // Quick operations without importing query package