Initial public release: OVRPlugin→OpenXR interoperability shim

An independent reimplementation of Meta's libOVRPlugin ABI on top of OpenXR, so
VrApi-era Meta Quest VR titles can run on non-Meta OpenXR runtimes (Monado,
Steam Frame) instead of being locked to Meta hardware. Original code only — no
Meta/Epic/Capcom binaries, headers, or assets. Includes a desktop harness that
drives the shim against Monado headless.

Scope/legal: interoperability; entitlement handling is out of scope. See README
for the legal/scope section and docs/ for the research trail and design notes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01D6sFYGXZPsq3v7xtcDES6g

packaging/_env.sh

@@ -0,0 +1,20 @@
+# Shared, portable path/tool detection for the packaging scripts. `source` this.
+# Derives the repo root from this file's location and auto-detects tool versions
+# under tools/ (or env overrides), so the repo builds/repacks anywhere.
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+PKG="$ROOT/packaging"
+SHIM_OUT="$ROOT/shim/build/arm64"
+
+# JDK: prefer a bundled tools/jdk-*, else an existing JAVA_HOME, else system java.
+_bundled_jdk="$(ls -d "$ROOT"/tools/jdk-* 2>/dev/null | head -1 || true)"
+if [ -n "${_bundled_jdk:-}" ]; then export JAVA_HOME="$_bundled_jdk"; fi
+KEYTOOL="${JAVA_HOME:+$JAVA_HOME/bin/}keytool"
+
+# Android build-tools dir (zipalign / apksigner / aapt2), e.g. tools/android-14.
+BT="$(ls -d "$ROOT"/tools/android-[0-9]* 2>/dev/null | head -1 || true)"
+
+# apktool jar (optional, for manifest work).
+APKTOOL_JAR="$ROOT/tools/apktool.jar"
+
+# Android NDK (for building the OpenXR loader).
+NDK="${ANDROID_NDK:-$(ls -d "$ROOT"/tools/android-ndk-* 2>/dev/null | head -1 || true)}"