- Remove KEY_COOKIES_BACKUP plaintext fallback from PreferencesManager
- getCookies() now fails closed (force re-login) if EncryptedSharedPreferences unavailable
- Set android:allowBackup="false" to prevent adb backup extraction of session data
- Add missing gradle-wrapper.jar to repo
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>