Native PRoot artifact

Android 10+ does not permit executing arbitrary dynamic binaries copied into the app data directory. PhoneAgent therefore packages the PRoot launcher and its Android dependencies as ABI-specific lib*.so APK native libraries and invokes PRoot through /system/bin/linker64.

PhoneAgent uses PRoot as a standalone launcher rather than exposing a Termux prefix. stage-termux-runtime.ps1 downloads pinned official Termux packages, verifies SHA-256, extracts only PRoot and its two dependencies, changes the libtalloc.so.2 dependency to the APK-safe libtalloc.so name, and stages the files as native libraries. Hardcoded loader and temporary paths are not used: PROOT_LOADER, PROOT_TMP_DIR, and LD_LIBRARY_PATH are set explicitly at runtime.

Expected layout:

core/runtime/src/main/jniLibs/arm64-v8a/libproot.so
core/runtime/src/main/jniLibs/arm64-v8a/libproot-loader.so
core/runtime/src/main/jniLibs/arm64-v8a/libtalloc.so
core/runtime/src/main/jniLibs/arm64-v8a/libandroid-shmem.so
core/runtime/src/main/jniLibs/x86_64/libproot.so
...

The source tree contains the verified staged ELF files so debug APKs exercise the real runtime. Re-running stage-termux-runtime.ps1 from an empty cache must reproduce their checksums. The GPL-2.0 Termux PRoot source, package recipes and exact revision are represented by build-termux-runtime.sh and the manual Native PRoot runtime workflow. A release must publish source, staging/build logs, licenses and checksums alongside the APK.

The phoneagent_pty JNI library is built from core/runtime/src/main/cpp with the pinned NDK. It uses Android's forkpty, supports input, output, resize and signals, and connects the interactive Debian shell to the Compose terminal screen.

ARM64 on-device validation remains mandatory before publishing a release.