Reject exact manifest destinations that are not covered by the last committed ownership set before creating a baseline or parking version.ini. Align Windows device-name validation with the confined filesystem backend and keep cleanup capability-relative.
Replace recursive downloaded-game removal with an empty ownership generation. The operation now removes only proven-owned files and the sentinel, preserves unknown files and directories, and remains recoverable and idempotent across crashes.
Test Plan:
- just clippy
- just test
- just fmt (Rust, TOML, and Prettier completed; rumdl still reports 39 pre-existing issues)