experiment: LivingPlane repeatable + standalone UE runtime module (L164)

Readback barrier fix (GL_TEXTURE_UPDATE_BARRIER_BIT before glGetTexImage); check_repeatability.py compares full-field
checksums across query/capture settings - Intel GPU PASS (3b9d45905c7aafff), llvmpipe PASS, mismatch control fails.
New runtime module VoxelForgeLivingPlane (separate from generation): RDG global shader (Shaders/LivingPlane.usf),
ping-pong RGBA32F render targets, actor with WPO plane and object inputs, no CPU readback. Compiles in Linux UE 5.7.
Windows build: Source/VoxelForgeLivingPlane/*, Shaders/LivingPlane.usf, VoxelForge.uplugin. Setup: UE-SETUP.md.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016dhxM43dnWvUu2B5Ph1iG1

Experiments/LivingPlane/build.sh

@@ -3,7 +3,7 @@ set -euo pipefail
 
 SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
 PLUGIN_ROOT="$(cd -- "${SCRIPT_DIR}/../.." && pwd)"
-OUTPUT_DIR="${PLUGIN_ROOT}/Saved/Linux/l163"
+OUTPUT_DIR="${PLUGIN_ROOT}/Saved/Linux/l164"
 CXX="${CXX:-g++}"
 
 command -v "${CXX}" >/dev/null || { echo "C++ compiler not found: ${CXX}" >&2; exit 2; }