* Preserve spoiler files and serialize update reloads
* Surface spoiler removal reload failures and allow disabled-state retry
* Address review feedback on spoiler update lifecycle
Only remove the spoiler file when the user unchecks the setting; opening
Settings no longer queues an unrequested reload for a leftover file.
Remove the spoilersUpdatedSuccessfully signal, which had no receiver.
* Fix spoiler settings state after reopen and while disabled
Reopen Settings while an application-owned update is running: the new page
now observes that updater, so the button reads Updating... and re-enables
on completion instead of offering a second update that cancels the first.
Observation does not take ownership: only updaters the page creates are
retired with deleteLater, because the launch check is stack-allocated.
When spoilers are off, the hint now describes what Reload Card Database
actually does, stays readable, and wraps instead of clipping.
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Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>