Solves the core usability problem of zero-knowledge encryption: on page reload
the in-memory DEK is lost, so the user can't decrypt their data even though their
JWT is still valid. Previously they had to close the tab and re-login from scratch.
Changes:
- Persist wrapped_dek/wrapped_dek_iv in the auth store (zustand persist). Safe:
it's AES-GCM ciphertext, useless without the password KEK — the server already
stores the same ciphertext. login/register/recover all save the wrapped DEK;
logout clears it.
- New UnlockPage: minimal password-only form. Re-derives the DEK locally via
unlockWithPassword (no API call — the JWT is still valid). Falls back to
deriveAuthAndEncKeys for Phase 1 compat accounts. Links to /login and /recover.
- ProtectedRoute now checks hasEncKey() after isAuthenticated: authenticated but
no in-memory DEK → redirect to /unlock.
- /unlock route in App.tsx (public, alongside login/register/recover).
Flow: login → browse → reload page → unlock screen → enter password → dashboard
loads with decrypted data. No full re-login needed.
Verified: npm build clean, 20 tests pass.
46f413975c