Bake a caption strip onto every posted screenshot composite — status + name +
the spec that produces it — for changed, added, and removed; removed now shows
the old baseline image (was a text-only line). Zero native-dep: an embedded
public-domain 8x8 bitmap font (font8x8.ts) rendered by image-ops `withBottomLabel`;
the name→spec attribution is factored out of gen-manifest into a shared
`spec-map.ts` resolver. Bottom strip, colour per status (green/red/orange).
Applies in both compare (drift gate) and changelog (git-history diff), and
post-discord now attaches the captioned removed images.
Also raise the per-engine drift floor 0.2% → 0.5% (changedRatio) to absorb the
sub-1% inter-run flakiness seen after the re-baseline, while still catching real
localized changes.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
New tooling in tests/tools/screenshots/ (TypeScript via tsx):
- compare.ts: one pixelmatch engine (AA-excluded), connected-component
"where to look" boxes, old|new+boxes|heatmap triptych, per-engine floors.
- promote.ts: churn-free updater — overwrite a baseline only when decoded
pixels differ beyond the floor, copying CI bytes verbatim (no re-encode
churn); pulls a CI run via `gh run download` or a local --from dir.
- post-discord.ts: always-on CI-on-main report (SHA + e2e status + the
track-only runtime-perf table), then screenshot triptychs, batched +
size-capped + flood-collapsed + 429-aware.
- perf-report.ts: perf table with Δ vs the previous main run (via gh).
- changelog.ts: no-build git-history baseline differ (Discord trigger B).
- noise.ts / gen-manifest.ts: calibration + manifest generation.
CI wiring:
- wasm-build.yml: post-test step runs the gate + report on the already-
produced test-results (no extra build); report-only (continue-on-error),
posts only on push to main, inert without DISCORD_WEBHOOK_URL.
- ci-ubicloud.yml: secrets: inherit (pass the webhook through).
- screenshot-changelog.yml: ~30s no-build changelog on baseline changes.
screenshot-manifest.json: canonical 354-name set + best-effort engine tags
(313 chromium-swiftshader / 41 firefox-llvmpipe).
Normalize scale:'device'->'css' across 18 spec files (no-op at CI DSF=1)
so committed baselines are uniformly css-scaled.
Design: CI's Linux render is the single source of truth; no pinned
container (accept rare env drift -> re-promote); dev commits via promote.
Replaces the byte-cmp compare-screenshots.sh + file-size-proxy
update-baseline-screenshots.sh (kept for now until the first re-baseline).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
