feat(offsite): 异地副本加入 registry 用户镜像，按摘要加密去重，索引按版本保留 14 天，新增 fetch-images 回推恢复

cmd/felis/run.go

@@ -13,7 +13,7 @@ Usage:
 Commands:
   migrate up        Apply embedded database migrations under an advisory lock (snapshots the database first)
   db                Back up, verify, list and restore the control-plane database (backup|restore|verify|list|check)
-  offsite           Copy world archives and database bundles to an off-site bucket, and fetch them back (sync|status|list|fetch-db|fetch-worlds|keygen)
+  offsite           Copy world archives, database bundles and user images to an off-site bucket, and fetch them back (sync|status|list|fetch-db|fetch-worlds|fetch-images|keygen)
   operator          Run the MinecraftServer controller-manager
   api               Run the felis-api HTTP server
   nano              Run the Felis-nano hasJoined multiplexer (multi-Yggdrasil, no control plane)