A False platform unload now returns False and retains the runtime
record so live entities keep their database. Sensor names and device
labels re-derive from the current snapshot so child renames
propagate; unique_ids stay child-id based.
Four sensors per active child read the coordinator snapshot: quests
due today (carrying the panel payload that omits missed instances plus
the admin payload that includes them, D-009), completed, remaining, and
completion percentage (100 on a zero-quest day). Platform forwarding
wired through the harness's entity registry stand-ins.