Replaces the crypto test bench with the three screens the client actually
needs. PMA.Vault holds the decrypted snapshot and answers the search;
mainApk builds unlock/list/detail in code rather than three .fmx files.
Two safety rules live in the UI because nowhere else can hold them: the
plaintext is dropped when the app backgrounds (screen hidden on
WillBecomeInactive, which precedes the recents-preview capture), and the
clipboard is cleared after 45 s only if it still holds what we put there.
The search deliberately ignores the password field.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>