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>
9a613239f2