Fifth slice of the app.js split. Moves the scheduled encrypted-backup
feature (config, retention, runAutoBackupNow/runAutoBackupIfDue) to
js/app.backup.js. Pure declarations + two consts, no top-level side effects
→ loads before app.js; uses encryptExportPayload (app.import.js), Bridge,
api, state via shared global scope at call time.
- Byte-for-byte identical extraction; no duplicate const; no top-level
backup reference left in app.js; syntax OK on all six app parts.
- index.html + BuildAssets whitelist + harness APP_PARTS updated; assets
regenerated (manifest embeds all 7 ordered JS files).
- 55/55 tests green.
app.js: 11936 → 9900 lines — now under 10k. Five modules extracted
(~2000 lines): argon2 → crypto → totp → import → backup → app → sync.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
r-zakarya