- Rewrite .gitignore with proper sections; add ignores for common
Android/IDE/OS artifacts (*.so, *.hprof, app/release/, Thumbs.db,
.vscode/, *.swp).
- Track gradle/wrapper/gradle-wrapper.jar so ./gradlew works after a
fresh clone (the previous negation rule was a no-op without a prior
*.jar ignore, so the jar was never committed).
- Stop tracking the local .zcode/ tooling directory (kept on disk).
