Eager-load S3 on volume backup lists and add an S3 status column with
Configured/Unavailable/Not set badges. Surface Local vs S3 on the
persistent storages backup column. Move service resource domain links
to a globe action in the card footer, and update related tests and grid CSS.
Add polymorphic volume backup scheduling for persistent volumes and directories, expose schedule management via API, and reorganize backup configuration and execution views.