Add thread minimap inset gallery variants

Merged
TE
8d ago
+108-19

Summary

Lawrence's ask was: “needs more left padding”. This PR adds a gallery-only comparison for the thread minimap edge spacing while preserving the existing gap scenarios:

  • keeps the current gap-4-chosen, gap-8, and gap-12 gallery variants;
  • adds an unmodified current-placement baseline plus 4, 8, 12, and 16 px exploratory pane-edge candidates;
  • leaves railPlacement, useRailPlacement, CSS, and production defaults unchanged so the selected token can be coordinated with the placement work in #26641.

The values are candidates for rendered comparison, not claims about private-image pixel scale. The rendered 8 px candidate is preferred for the production follow-up: it separates the resting ticks from the pane edge while leaving more text-side room than 12 or 16 px. That preference is visual judgment, not a pixel-scale claim about reference images. The production change must retain gutter compression and the existing maximum text overlap through the placement work in #26641. No private captures are included.

Evidence

  • Exact-head retained gallery artifact: gallery-advisory-27192-b8499b80ff619e887761ef59d9ad04cfe60332e8. Includes all eight narrow variants at 780 CSS px in light/dark Chromium, plus base images for the three existing gap variants. gallery-review.json binds head b8499b80ff619e887761ef59d9ad04cfe60332e8 to base 3004f44a390858dc8b928f7c6a8c7b2561abfae1; all ten new inset images are ready. New variants have no same-name base image.
  • Gallery matrix run 40807997283: 16 window-frame cases across eight variants and two appearances, rendered in both Chromium and WebKit (32 ready stages). This is render-health evidence only: the default window frame was used, and images were not retained; retained exact-head narrow visual comparison is in the advisory artifact above; source snapshot d44e6027c9cc22c3752e1f3449731f9f39772eab.
  • Focused test run 40808539178: bun test test/thread-minimap-inset-variants.test.ts, 1/1 passed; source snapshot 12035ab9cd903a9b632eb45533e87fe51c6e3271.
  • Web lint run 40809243907: bun run lint passed; source snapshot 190d98241060d7e3d6d8d90f128774dbb59f7dc5.
  • No Swift files changed.

Agent session: agent session