feat: curate landing-page examples to a featured subset

[TMHSDigital]

What this is

The landing page's Render Result section rendered all 40 example cards in a two-column grid — 9,948px of scroll at 1280px (24,788px at 390px), the longest page on the site. PR #113 gave /gallery/ search, filters, and density controls; this PR makes the landing page a showcase that delegates enumeration to the gallery. No search/filter/toggle is added to the landing page — that is what /gallery/ is for.

All changes go through the generators (scripts/site/build_site.py + scripts/site/template.html.j2, driven by examples/gallery.json); no generated file is hand-edited (docs/index.html is a gitignored build output; docs/gallery/ regenerates byte-identical — verified).

Featured-selection mechanism

• examples/gallery.json entries may now carry a featured_rank integer.
• build_site.py::pick_featured() sorts entries with a rank into featured_examples and passes it to the template. When nothing is curated (empty list), the template falls back to the full list — the section can never go blank.
• No hand-maintained duplicate list in the generator or template: the data file is the only place the set lives.

Featured set and why

Rank order as rendered: car-mirror-symmetry, soccer-ball-goldberg, damped-track-aim, light-link-studio, collision-hull-proxy, armature-bend, bmesh-gear, color-attribute-wheel.

The two pinned calibration members (armature-bend, bmesh-gear — third member damped-track-aim also included) plus the most striking recent work, ordered for subject and palette variety: automotive (Mirror), sports geometry (Goldberg), constraints (golden needle array), lighting narrative (linked/unlinked), game pipeline (wireframe hull), armature weights (pink/teal gradient), bmesh (gold gear), color science (rainbow wheel). Renders were reviewed individually, not picked from names.

Section changes

• Grid shows the 8 featured cards; anatomy, dark theme, typography unchanged.
• Panel-head counter is now honest: 8 of 40 frames (was 40 frames).
• Gallery link is the section's primary CTA: an orange button above the grid ("Browse all 40 examples in the gallery →"), visible within the first viewport of the section. The original text link remains below the grid as a secondary.

Landing-page height (live measurement, all lazy images loaded)

Viewport	Before (current live site)	After (this branch, local)
1280×800	9,948px	4,847px (−51.3%)
390×844	24,788px	10,203px (−58.8%)

Verification — live run (Playwright, Chromium 148, local python -m http.server over docs/)

26 assertions, all passing; screenshots reviewed, not just load-checked:

• Desktop: 8 cards in featured_rank order, counter text, CTA above the grid and within the first ~1.1 viewports (y≈847), href gallery/.
• Mobile 390px: 8 cards, single column, counter, CTA above grid.
• No-JS landing: 8 featured cards render, CTA present, and clicking it navigates to /gallery/ where all 40 cards render.
• /gallery/ regression: compact default, search (needle → 1), tag AND search (bmesh+gear → 1), hash written and restored on a fresh page, detailed toggle, sticky controls at exactly top:46, no-JS 40/40 cards. PR feat: add search, density toggle, and sticky controls to gallery index #113 behavior intact. (The gallery's own CSS/JS was not touched; its build output is byte-identical on this branch.)
• Alt text: re-read the 8 generated landing <img alt>s ({name} render — the landing template never used teaches-based alts, so the dotted-path truncation class does not apply); complete. All 40 /gallery/ alts untouched.

Other generated pages with the same all-inline problem

Checked while in the template: none pathological. The landing page's Skills section lists 12 compact two-line rows (~700px), Rules a 6-row table, Snippets/Templates link chips, Changelog 2 entries — all enumeration-sized and appropriate for a landing page. /gallery/ detail pages are one-example-each by construction. No further action needed.

Inspection only (not live-run)

• Firefox/Safari rendering (all captures Chromium).
• The empty-featured_rank fallback path (template renders all 40 when nothing is curated) — verified by code reading; the shipped config has 8 ranked entries.

Release note

feat: subject — release.yml will cut a minor on merge. docs/index.html is rebuilt by the Pages deploy from the same template + data, so served and reviewed output cannot drift.