Add native Android (Jetpack Compose) app port

[gmegidish]

Summary

• Native Kotlin/Jetpack Compose port of the iOS Milliways app onto the existing Android skeleton: Welcome, Menu, Item Detail, Order, Delivery, and Account screens, wired together with Navigation Compose and iOS-style push/modal slide transitions.
• Preserves the app's intentional test bugs (empty-cart crash, negative-total crash from a frozen coupon, the delivery screen's fake never-completing countdown, pop-to-root on delivery close) since this is an intention-test app.
• Replaces the default launcher icon with a proper adaptive icon (previous flat icon was being auto-shrunk by the launcher).
• Adds build/lint targets to android/Makefile and an apk target to the root Makefile.
• Fixes a pre-existing path bug in .github/workflows/release.yml and run-tests.yml where iOS build artifacts were referenced at build/... instead of their actual location ios/build/..., and adds an Android job to release.yml that builds and uploads the debug APK to GitHub Releases.

Test plan

• Manually walked the full flow on an Android emulator against the iOS simulator side-by-side (screenshots compared screen-by-screen)
• Verified both intentional crash bugs reproduce (empty-cart place-order, negative-total place-order)
• Verified make build, make lint, and root make apk all succeed locally
• CI run on this PR (release job only triggers on version tags, so it won't run here — verify on next tag push)