R-487: the local backup lists are keyed on the drives, not on what is
deployed — a removed app whose unit was kept is listed with the restore
that reinstalls it, the picker answers for it, and the restore opens the
unit where it sits. R-491: a removal clears the app's update hold.
R-490: /api/system/info reaches the API router and reads the default
storage path. R-489: volumes_removed is the real before/after difference,
[] when none. R-476: a Tier-2 copy is dated by its data, not its manifest.
R-456: the boot-orphan rule is pinned. Every fix red-proofed.
