Make sync more atomic

[elasticroentgen]

• rclone to a temp folder in the bucket first
• then do an rclone move into the real target
• make it configurable

[elasticroentgen]

added and deployed. Check after next run tomorrow on how it went.

[elasticroentgen]

forgot to bump helm chart version. check again tomorrow

[elasticroentgen]

atomic mode active. need to verify with new snapshot on source.