==================== POC OUTPUT ====================
[POC] GL_RENDERER: ANGLE (Google, Vulkan 1.3.0 (SwiftShader Device (Subzero) (0x0000C0DE)), SwiftShader driver)
[POC] GL_VERSION : WebGL 2.0 (OpenGL ES 3.0 Chromium)
[POC] Dimensions : W=512 H=512 N=4  layer=1 MiB  total=4 MiB
[POC] 
[POC] [CONTROL] prime + 1 upload (prune threshold NOT met):
[POC]   layer 1: nonzero=0 marker(0xAB)=0
[POC]   layer 2: nonzero=0 marker(0xAB)=0
[POC]   layer 3: nonzero=0 marker(0xAB)=0
[POC]   total nonzero=0 marker=0
[POC] 
[POC] [TRIGGER] prime + 20 uploads (>=16 MiB -> prune fires on !valid() ImageHelper):
[POC]   layer 1: nonzero=1048576 marker(0xAB)=1048576
[POC]   layer 2: nonzero=1048576 marker(0xAB)=1048576
[POC]   layer 3: nonzero=1048576 marker(0xAB)=1048576
[POC]   total nonzero=3145728 marker=3145728
[POC]   sample: layer 1 @+0: 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab 0xab
[POC] 
[POC] ---
[POC] ==> RESULT: LEAK CONFIRMED
[POC]     Robust-init Clear was wrongly pruned; layers 1..3 contain 3145728 stale GPU-memory bytes (3145728 = marker 0xAB).
[POC]     Control (no prune) returned all-zero -> root cause is the stale-prune path.
====================================================

STATUS: VULNERABLE (uninitialized GPU memory leaked via WebGL2)
Full log: /tmp/chrome-poc-1009.log