Fix remote.meta.sync TTL issue (#8021) (#8030)

* Fix remote.meta.sync TTL issue (#8021)

Remote entries should not have TTL applied because they represent files
in remote storage, not local SeaweedFS files. When TTL was configured on
a prefix, remote.meta.sync would create entries that immediately expired,
causing them to be deleted and recreated on each sync.

Changes:
- Set TtlSec=0 explicitly when creating remote entries in remote.meta.sync
- Skip TTL application in CreateEntry handler for entries with Remote field set

Fixes #8021

* Add TTL protection for remote entries in update path

- Set TtlSec=0 in doSaveRemoteEntry before calling UpdateEntry
- Add server-side TTL protection in UpdateEntry handler for remote entries
- Ensures remote entries don't inherit or preserve TTL when updated

weed/shell/command_remote_mount.go

@@ -188,6 +188,7 @@ func doSaveRemoteEntry(client filer_pb.SeaweedFilerClient, localDir string, exis
 	existingEntry.Attributes.FileSize = uint64(remoteEntry.RemoteSize)
 	existingEntry.Attributes.Mtime = remoteEntry.RemoteMtime
 	existingEntry.Attributes.Md5 = nil
+	existingEntry.Attributes.TtlSec = 0 // Remote entries should not have TTL
 	existingEntry.Chunks = nil
 	existingEntry.Content = nil
 	_, updateErr := client.UpdateEntry(context.Background(), &filer_pb.UpdateEntryRequest{