Add android/demo — a minimal, dependency-free app (plain Android Views,
no Gradle/AGP/AndroidX/Compose) that calls the Phase-4 JNI core on-device
and displays the results. build-apk.sh drives the SDK build-tools directly
(aapt2 -> javac -> d8 -> zip -> zipalign -> apksigner), compiling against
android.jar alone so it needs no network and tolerates a very new system
JDK by routing the SDK tools through a JDK <= 21.
The app has three buttons -> platformFromUrl/platformDirName, classifyError,
and vttParse, each calling libcatacomb_core.so and showing the JSON.
Verified on an Android 14 (API 34) x86_64 emulator: installs, launches,
loads the .so, and returns correct JSON on-device
({"dir_name":"channels","display_name":"YouTube","icon":"..."} for a
YouTube URL). Output APK (out/, git-ignored): catacomb-spike-debug.apk,
v2+v3 signed, minSdk 24, native code for arm64-v8a + x86_64.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Implement the shared-Rust-core leg of the Android Stage-1 prototype
(docs/superpowers/specs/2026-06-27-android-stage1-prototype-plan.md).
android/rust/catacomb_core is a cdylib that reuses the pure desktop
modules (vtt, error_class, platform) verbatim via #[path] includes — no
logic fork — and exposes them to Kotlin over JNI as String-in/String-out
entry points:
RustCore.vttParse(vtt) -> JSON [{start,text},...]
RustCore.classifyError(log) -> JSON {class,label,hint}
RustCore.platformFromUrl(url) -> JSON {dir_name,display_name,icon}
RustCore.platformDirName(url) -> folder name
Built with panic=abort + per-entry catch_unwind so a Rust panic can never
unwind into the JVM. build.sh locates the NDK portably and cross-compiles
to arm64-v8a + x86_64, depositing the .so into app/src/main/jniLibs/.
Verified: cargo test (38 pass), llvm-readelf confirms all 4 JNI symbols
exported in the arm64 .so, and an end-to-end host-JVM round-trip
(System.load + call each native method) returns correct JSON.
Phases 2/3/5 (WebView-BotGuard anti-bot) remain device-only and untouched.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
