Documents WHY each version is pinned:
- cmake 3.25: 3.27+ rewrote Android-Determine.cmake with bugs
- NDK 26.1: NDK 27 scudo crashes on MTE devices (Nothing A059)
- JDK 17: Gradle 8.5 + AGP 8.2.0 official support
- ANDROID_NDK: cmake checks this, not ANDROID_NDK_HOME
Idempotent, works from clone or existing tree.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
