Bundle Python and adb so the app needs nothing installed

- app/build/fetch-deps.js downloads a standalone Python 3.12
  (python-build-standalone) for every build and adb from Google's
  platform-tools, pinned by SHA-256, and prunes what the server never
  uses. It replaces the Windows-only embeddable Python.
- The app runs the bundled Python with -I -u -B -X utf8, so a PYTHONHOME
  or PYTHONPATH meant for another Python can't break it and nothing is
  written inside the signed macOS bundle.
- An adb you already have still goes first, so two adb versions don't
  keep restarting each other's server. arm64 Linux has no official
  platform-tools and keeps using the system adb.
- ui/frame_apk.py reads APK badging (package, label, version, min SDK,
  ABIs, icon) from the binary manifest and resources.arsc, replacing
  aapt2. It matches aapt2 on nine F-Droid APKs and finds launcher icons
  the old path missed with adaptive icons.
- The app reads the computer's clipboard through Electron, so Linux no
  longer needs wl-clipboard or xclip.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/apks.md

@@ -18,7 +18,8 @@ python3 ui/frame_android.py list|launch|stop|remove|probe <package>
 Each APK becomes its own app, the way T3 Code is set up (see the instance
 section below), instead of going into Lepton Development:
 
-1. `aapt2` reads the package, label, version, ABIs and icon. APKs that need
+1. `ui/frame_apk.py` reads the package, label, version, ABIs and icon
+   (a stdlib parser of the binary manifest and resource table, so no Android SDK). APKs that need
    API > 30 or have no `arm64-v8a` build are refused.
 2. The APK, `frame/android/lepton-app.sh` (as `launch.sh`), `instance.id`,
    `meta.json`, the icon and the `lepton-show-flatscreen` marker go to