Boots release ely_app, waits 8s, screencaptures full screen, verifies:
- file >10KB, dims >100x100 via sips
- center 128x128 patch not ~white (via sips crop + stdlib PNG decode)
- stderr captured to /tmp/ely-verify-stderr.log on crash
Runs idempotently (kills stale ely_app on entry + trap cleanup on exit).
No new deps; pure bash + macOS sips + /usr/bin/python3 stdlib.
First real run: PASS, screenshot /tmp/ely-verify-20260511-005449.png,
center RGB ~(243,240,236) — app chrome paints, but web surface still
shows the GPUI welcome panel (no Servo content) — exactly what T15's
paint barrier should fix.
ZacharyZhang-NY