Lemenzo App Installer v2.4.2 — Offline-only final audit

Runtime behavior is unchanged from v2.4.1:
- 12 curated offline apps including F-Droid and Aurora Store.
- Individual Install and Install all.
- Installed / Not installed / Blocked / Missing.
- No updater, online repository client, or Play bridge.
- No INTERNET permission.
- Lazy package/version/SHA-256/signer verification before install.
- Launcher: Installer.
- In-app title: Lemenzo App Installer.

v2.4.2 fix:
- Restored the robust offline metadata generator for SDK-targeted APK signing
  (including Signal on Android 16 / SDK 36).
- Generator remains fail-closed and writes apps.json atomically only after all
  APKs pass package/version/signature checks.