feat: save and restore personal convars

[oldreceipt]

Personal gameinfo.gi values currently require hand editing and manual recovery after a game update. This adds saved convar name/value rows with enable/remove controls, Save only, and Save & apply. Personal values work without an FPS preset and remain separate from preset overrides when presets are changed or removed.

Optional recovery runs when Grimoire starts and before a modded launch. It patches the current valid game file only while Deadlock is stopped and Steam is not updating. Preferences are saved atomically outside gameinfo.gi; failed application remains visible after a successful save.

Validation:

• GitHub CI passes on Ubuntu, including the full test suite and build.
• Typecheck, lint, production build, locale check, and generated-manifest check pass in this isolated branch.
• 23 focused service/editor tests pass, covering reversible precedence, preset interactions, recovery guards, failed saves, and save/apply UI ordering.
• Full Windows suite: 1,298 passed, 12 failed, 15 skipped; also a steamRoots suite setup failure. Failures are the existing six CRLF fixture round trips and Windows-incompatible Wine/pgrep/symlink fixtures. The CRLF failures were reproduced against the unchanged base.
• Rendered the actual editor with isolated sample data in a browser preview. Native desktop automation remained unavailable; no real game files were changed for testing.

This PR targets this fork's main and is independent of the local-VPK replacement PR. Regenerate the locale manifest when combining both changes.