Increment 2 — authentication and account management.
- Gmail OAuth 2.0 via AppAuth (Authorization Code + PKCE, restricted
https://mail.google.com/ scope); redirect scheme derived from the client id.
- Generic IMAP/SMTP manual setup (host/port/security) with an Advanced section.
- Angus/Jakarta Mail IMAP client (password + XOAUTH2); "test connection" logs in
and lists folders before an account is saved.
- Android Keystore-backed AES-256-GCM credential store (encrypts the OAuth
AuthState / IMAP password); accounts + secrets persisted in Room (schema v2).
- AccountRepository + Hilt wiring; Settings accounts list (add / remove).
- Tests: GreenMail-backed IMAP client unit test; instrumented Keystore round-trip
and Angus Mail provider-resolution tests (green on the Android 17 emulator).
- Remove the placeholder Compose smoke test (the API 37 Compose-UI-test library
hits InputManager.getInstance); on-device rendering verified via screenshots.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>