hoelee f364084284 perf(images): WebP banners, text-only related cards, resized list thumbnails ...

Measured before/after with headless Chrome + CDP (not by eye):

- article banner: <picture> WebP q78 with the PNG as fallback, because the PNG
  must stay for og:image (social scrapers do not reliably render WebP cards).
  70 banners: 6.02 MB -> 2.52 MB (42%). JPEG measured *larger* than PNG here
  (q85 = 129%) — the art is flat terminal-style with sharp text edges.
- post page related cards: dropped four 1200x630 PNGs (183 KB) to display
  526x276 where the embedded code is illegible; now text-only cards with a
  category badge, date and reading time.
- list thumbnails (home + archive): new /og/thumb/<name>-{400,800}.webp served
  via srcset/sizes. Rows display at ~398px but were pulling full 1200x630 PNGs.
  Homepage thumbnails ~450 KB -> 62 KB; archive (71 rows) ~3.2 MB -> 436 KB.
- desktop banner capped at 720px centred: 67% -> 45% of a 900px viewport,
  keeping the art intact instead of cropping it.

Post page totals: images 277 KB -> 38 KB; page height 5758 -> 5065 (desktop)
and 9423 -> 8807 (mobile). Build: 163 pages.

Script: scripts/optimize-images.py; policy: docs/design-guide.md §3; runbook
step added to docs/ops-runbook.md.

2026-10-16 17:11:27 +08:00

42 KiB

1600x900px

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