Procedures for auditing apps/landing TERMINAL VELOCITY WebGL phase gates - driving the browser to exact playhead positions across the 9 scenes, screenshot discipline, scrub + VAT determinism (scrub down THEN rewind to the same playhead -> identical frame), FPS sampling at the risk scenes, draw-call + bundle-size probes vs budget, the blackout->dawn luminance-delta/strobe check at max scrub velocity, copy-parity vs landing/index.html, and reduced-motion + no-GL fallback verification. Load when running /gate or reviewing rendered GL output.