- Added moneroGetStoredPassword / moneroStorePassword keychain helpers
- moneroCreateWallet and moneroRestoreWallet accept storePw flag to save password to keychain
- moneroOpenExistingWallet accepts optional password (falls back to keychain lookup)
- Monero UI: 'Save password with Touch ID' checkbox hides password field, auto-generates random password, saves to keychain
- Monero UI: 'Open with Touch ID' button uses biometric auth + retrieves stored password
- Monero Settings card: enter wallet password to save with Touch ID for existing wallets
- logout() now async, calls moneroStop() to kill RPC process so re-login requires explicit wallet open