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/Source/LinuxOffscreenCapture.cpp

@@ -1,9 +1,12 @@
+#include "SourceStamp.h"
+
 #include <EGL/egl.h>
 #include <EGL/eglext.h>
 #include <GLES3/gl3.h>
 #include <png.h>
 
 #include <algorithm>
+
 #include <array>
 #include <cmath>
 #include <cstddef>
@@ -810,6 +813,8 @@ void main()
 
 int main(int argc,char** argv)
 {
+    VoxelForgePrintSourceStamp();
+    if(argc==2&&std::string_view(argv[1])=="--print-source-stamp")return 0;
     if(argc<3)
     {
         std::fprintf(stderr,"Usage: %s scene.vfmesh output.png [--size=WIDTHxHEIGHT] [--fov-deg=90] [--height-range-m=N] [--height-center-m=N] [--camera-m=X,Y,Z] [--yaw-deg=N] [--pitch-deg=N] [--shade=readable|normal] [--height-tint=on|off] [--headlamp=on|off] [--light-direction=X,Y,Z] [--tile-edges=on|off] [--tile-skirts=on|off] [--tile-edge-width-m=N] [--clip-plane=NX,NY,NZ,D] [--focus-region=X,Y,Z,R]\n",argv[0]);
@@ -1037,4 +1042,3 @@ int main(int argc,char** argv)
         HeightTint,Headlamp,TileEdges,
         TileEdgeWidthMeters,HasLightDirection,LightDirection,ClipPlaneEnabled,ClipPlane)?0:3;
 }
-