JT7 for Android: source code

JT7 for Android is a modified build of Winlator (https://github.com/brunodev85/winlator-app), which is free software
under the GNU Lesser General Public License v2.1 (see winlator-app/LICENSE). This archive is the complete source of the
modified app, as built for the JT7 site.

What changed from Winlator 11.2 (the "jt7" branch):
- App name "JT7", JT7 icon, package id com.jt7.game (same length as com.winlator, so jt7/package_rename.py swaps the
  install path byte for byte inside the bundled archives in app/src/main/assets).
- A start screen, com.winlator.jt7.JT7Activity, that installs, updates and starts Project Playtime Rewrite from the
  JT7 site, and helps set up the Tailscale app for multiplayer.
- Two touch layouts, JT7 Survivor and JT7 Monster (assets/inputcontrols/profiles/controls-5.icp and -6.icp, made by
  jt7/make_controls.py).
- RootFSInstaller.install takes a callback; release builds are signed with a key that is not part of this archive.

Building: Java 17, Android SDK 35, NDK 24.0.8215888, CMake 3.22.1, then "gradlew assembleDebug" in winlator-app
(give Gradle about 6 GB of memory: org.gradle.jvmargs=-Xmx6g).
