Summary

This PR now contains only the Android/runtime-host work that is still missing from main after rebasing onto 8cd1429:

• build and run the Android unit-test app against API level 35;
• align the app's local default with the NDK r28c version already used by CI, while retaining the -PndkVersion override;
• accept comma-separated Gradle ABI filters and choose sensible arm64/x86_64 defaults for local and injected builds;
• send native debug-trace output to a dedicated JsRuntimeHost logcat tag; and
• replace the inspector's char16_t/uint16_t type-punning buffer with a correctly typed std::vector<uint16_t>.

The Android setup instructions now name the SDK and NDK versions required by this test configuration.

Work already superseded or removed

• #118 (70ba1e5) already made the project build with NDK r28c and moved Android CI to it. #159 (49e2980) migrated CI to GitHub Actions, and #164 (7239f91) restored the connected-emulator test. This PR therefore only advances that emulator from API 33 to API 35 and aligns the local Gradle default.
• #133 (06d4420) aligned the supported Android and Windows prebuilts on V8 11. The old three-argument/four-argument inspector connect split is no longer applicable and has been removed from this PR.
• The proposed android-jsc 250231.0.0 -> 294992.0.0 bump has been removed. 294992 is published under a different Maven path than this repository consumes, and its arm64 binary still has 4 KiB ELF load alignment, so it would not solve Android 15/Android XR 16 KiB page compatibility. #206 handles the replacement separately by consuming Bun's pinned Android WebKit/JSC archives for arm64-v8a and x86_64, relinking them as libjsc.so, and raising only the JSC path to API 28.
• The rebase conflict with #176 (f07d991) was resolved while preserving its Hermes and host-compiler CMake arguments.

Validation

• npm ci in Tests.
• Fresh API 35 / NDK 28.2.13676358 arm64 debug builds with both V8 and JavaScriptCore.
• Connected Android tests on an API 35 arm64 emulator with both engines: 1/1 test passed for V8 and 1/1 for JavaScriptCore.
• ELF program-header audit: the newly built JNI library, libc++_shared.so, and the supported V8 prebuilt all use 16 KiB load alignment. The legacy JSC prebuilt validated by this branch remains 4 KiB aligned; its intentionally separate replacement in #206 produces 16 KiB-aligned libjsc.so binaries for arm64-v8a and x86_64.
• git diff --check.

Scope

This is Android API/toolchain and runtime-host preparation; it is not by itself complete BabylonNative Android XR support. OpenXR loader/manifest wiring, lifecycle and input integration, arm64 Android CI/ELF auditing, and validation on Galaxy XR/XREAL hardware remain separate follow-up work (principally BabylonNative#1766).