Faster Corpse Cleanup

## Faster Corpse Cleanup 1.0.4 Changes since 1.0.0: - Added **Extra corpse cleanup**, enabled by default. Turning it off keeps timer changes active while skipping extra corpse checks and removal requests. - Restricted corpse checks to active missions, removing that work from the ship. - Stopped repeatedly checking timer records once the selected settings have been applied. - Reduced repeated corpse lookups through caching, bounded checks and retry delays after failed reads. - Staggered extra removal requests when multiple corpses expire together. Large backlogs may take longer than the selected delay. - Fixed corpse-age tracking resetting when ownership or status metadata changes. - Prevented nested callbacks from scanning the same update twice. - Fixed tracked corpses being discarded after an unreadable queue snapshot. - Moved settings saves to the background and combined rapid changes. Existing settings carry over, and the new switch is saved between sessions. - Replaced individual corpse-tracking logs with occasional activity summaries.