feat(android): add Android target kinds

Summary

• Add Once-native Android Starlark target kinds for android_resource, android_library, and android_binary.
• Add Kotlin source support through Starlark toolchain attrs, with Java compiled first and Kotlin compiled into the final class output.
• Add android_binary run support through direct adb actions that build the APK first, install it, resolve the launcher activity, and start it.
• Add bundled Android starter examples, including a Kotlin app that depends on a Java Android library and shared resources, plus graph guide and prelude reference docs.

Testing

• mise exec -- cargo fmt --all -- --check
• mise exec -- cargo test -p once-frontend
• mise exec -- cargo test -p once-cli commands::graph
• git diff --check
• mise run android:install-sdk
• mise exec -- kotlinc -version
• Schema smoke: mise exec -- cargo run -p once-cli -- query schema android_binary --format json
• Kotlin library build smoke: mise exec -- target/debug/once -C crates/once-frontend/prelude/examples/android-library-minimal build libs/greeting/Greeting --format json
• Kotlin APK build smoke: mise exec -- target/debug/once -C crates/once-frontend/prelude/examples/android-binary-minimal build apps/hello/Hello --format json
• Android emulator smoke: booted an API 35 AVD, ran mise exec -- target/debug/once -C crates/once-frontend/prelude/examples/android-binary-minimal run apps/hello/Hello --format json, then verified dev.once.hello/.MainActivity as the resumed activity with adb shell dumpsys activity activities.

No GitHub comments yet.