feat: 31 languages + disk safety panel + electron auto-updater + VM uninstall

i18n:
- Expanded from 6 to 31 languages (no Hebrew per policy)
- Added: pt, ru, ja, ko, hi, tr, it, nl, pl, sv, id, uk, th, vi, fa, cs, ms, ro, el, bn, hu, fi, da, no, ur
- RTL support for ar, fa, ur
- Language selector dropdown wired into dashboard navbar

Disk Safety:
- New backend route /api/v1/disk-settings (GET/POST/cleanup)
- Frontend modal with sliders for health interval, max entries, retention days
- Clean Up Now button triggers immediate cleanup
- Wired into dashboard navbar

Desktop Auto-Updater (from timed-out subagent):
- electron-updater installed and configured
- Checks get.dashcaddy.net/release/ for updates
- Publish config added to package.json

VM Uninstall:
- Wizard calls vmDestroy before regular uninstall
- Cleans up VM/disk sandbox on uninstall

Cleanup:
- Recursive data nesting guard (nesting-guard.js)
- Removed 242MB of data/data/data/ duplicates

dashcaddy-api/src/utilities/config-schema.js

@@ -14,7 +14,7 @@ const KNOWN_KEYS = [
   'configurationType', 'defaults', 'customLogo', 'customFavicon',
   'dashboardTitle', 'tailscale', 'license', 'skipped',
   'routingMode', 'domain', 'email', 'defaultIP', 'pylon',
-  'customLogoDark', 'customLogoLight'
+  'customLogoDark', 'customLogoLight', 'language'
 ];
 
 /**