- Single atomic write instead of two-phase (prevents split state on crash)
- Timestamped pre-import backup (multiple imports don't overwrite safety net)
- Fix UI refresh: correct function names + refresh globalSettings/alwaysOnTop
- Zero sensitive buffers (key, plaintext, decrypted) after use
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
AES-256-GCM + PBKDF2 encrypted config backup (.mhu files).
Export/import all accounts, settings, and history.
Pre-import safety backup of current config.
Password modal with confirmation for export.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
