tools(verify): fast/medium/full verification tiers with a compiled-in source stamp (L39); research R6

BuildLinux.sh hashes a sorted manifest of compiled inputs into VOXELFORGE_SOURCE_STAMP, printed first by
every executable; Standalone/Tools/verify/verify.py checks it before and after each tier and records
binary/input hashes and the resolved recipe, style map and layout. Fast (163 s) runs on the canonical owner
world only and asserts FI Style 2 / SW Style 1; medium (8 min) and full (26 min) add the style matrix,
GCC, determinism and cost. Controls: stale source, mislabelled style-0 owner, all-black capture, L30/L31,
L35/L36 and the L38 step are all rejected. No geometry change; owner hashes identical to L37.
Research R6: leak table, generator contract and a 10-step metre-native migration plan.

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

Standalone/BuildLinux.sh

@@ -7,6 +7,8 @@ fi
 
 SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
 ROOT="$SCRIPT_DIR"
+PROJECT_ROOT="$(cd -- "$ROOT/.." && pwd)"
+VERIFY_DIR="$ROOT/Tools/verify"
 COMPILER="clang++-19"
 VARIANT="clang19"
 FP_CONTRACT="off"
@@ -41,6 +43,15 @@ BIN_DIR="${VOXELFORGE_BIN_DIR:-$ROOT/bin/linux}"
 BUILD_DIR="$BUILD_ROOT/linux-$VARIANT"
 mkdir -p "$BUILD_DIR/wrappers" "$BUILD_DIR/objects" "$BIN_DIR"
 
+STAMP_HELPER="$VERIFY_DIR/source_stamp.py"
+STAMP_ARGS=()
+if [[ "${VOXELFORGE_INCLUDE_UNREAL_ADAPTER:-0}" == "1" ]]; then
+    STAMP_ARGS+=(--include-unreal-adapter)
+fi
+SOURCE_STAMP="$(python3 -B "$STAMP_HELPER" stamp --root "$PROJECT_ROOT" "${STAMP_ARGS[@]}")"
+python3 -B "$STAMP_HELPER" write-manifest --root "$PROJECT_ROOT" --output "$BUILD_DIR/source-manifest.txt" "${STAMP_ARGS[@]}" >/dev/null
+printf 'Source stamp: %s\n' "$SOURCE_STAMP"
+
 INCLUDES=(
     "-I$ROOT/Core/include"
     "-I$ROOT/Core/src"
@@ -52,6 +63,7 @@ INCLUDES=(
 FLAGS=(
     -std=c++20 -O2 -mavx2 -mfma -fno-fast-math
     -fexceptions -pthread "${INCLUDES[@]}"
+    "-DVOXELFORGE_SOURCE_STAMP=\"$SOURCE_STAMP\""
 )
 if [[ "$FP_CONTRACT" != "default" ]]; then
     FLAGS+=("-ffp-contract=$FP_CONTRACT")
@@ -122,8 +134,15 @@ OUTPUT="$BIN_DIR/VoxelForgeCoreHeadless-$VARIANT"
 "$COMPILER" -pthread "${LEGACY_OBJECTS[@]}" "$CORE_LIBRARY" -o "$OUTPUT"
 CAPTURE_OUTPUT="$BIN_DIR/VoxelForgeOffscreenCapture-$VARIANT"
 "$COMPILER" -std=c++20 -O2 -fno-fast-math -pthread \
+    "-DVOXELFORGE_SOURCE_STAMP=\"$SOURCE_STAMP\"" -I"$ROOT/Source" \
     "$ROOT/Source/LinuxOffscreenCapture.cpp" -o "$CAPTURE_OUTPUT" \
     $(pkg-config --cflags --libs egl glesv2 libpng)
+
+POST_BUILD_STAMP="$(python3 -B "$STAMP_HELPER" stamp --root "$PROJECT_ROOT" "${STAMP_ARGS[@]}")"
+if [[ "$POST_BUILD_STAMP" != "$SOURCE_STAMP" ]]; then
+    printf 'Source changed during build: before=%s after=%s\n' "$SOURCE_STAMP" "$POST_BUILD_STAMP" >&2
+    exit 1
+fi
 printf 'Built Core library: %s\nBuilt headless benchmark: %s\n' "$CORE_LIBRARY" "$OUTPUT"
 printf 'Built EGL offscreen capture: %s\n' "$CAPTURE_OUTPUT"
 printf 'Compiler: %s | variant: %s | fp-contract: %s | jobs: %s\n' "$COMPILER" "$VARIANT" "$FP_CONTRACT" "$JOBS"