fix(web): all accent text and icons use accent-fg (#5318)

The raw accent fails AA as text on every dark surface, not only on its
own tint: 3.04:1 on the page, 2.70 on iron, 2.21 on slate, against 4.5.
accent-fg (the house formula, 45% toward parchment) measures 5.62 at
worst across both modes. The operator chose the readable colour over the
signature teal for text, on 2026-10-08.

- 36 sites swap. They are 35 Tailwind uses: links, "Now playing", the
  ingest progress line, active shuffle/repeat, the liked heart, the app
  download icon and its hover. The last is the alphabet rail's pending
  spinner in CSS. Icons follow the text: as graphics they need only
  3:1, and the raw accent misses even that on iron.
- check-tint-contrast adds accent to TEXT_NEVER_RAW, so a new raw
  text-accent or color: var(--fs-accent) fails the web lane. Run against
  the files before the swap, it finds all 36. Borders, rings and fills
  keep the raw accent.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/routes/admin/tuning/+page.svelte

@@ -495,7 +495,7 @@
                   {/each}
                   {#if s.points.length > 1}
                     <polyline
-                      class="text-accent"
+                      class="text-accent-fg"
                       points={sparkPoints(s)}
                       fill="none"
                       stroke="currentColor"
@@ -503,7 +503,7 @@
                     />
                   {:else if s.points.length === 1}
                     <circle
-                      class="text-accent"
+                      class="text-accent-fg"
                       cx={xFor(s.points[0].week_start)}
                       cy={SPARK_H - s.points[0].skip_rate * SPARK_H}
                       r="2" fill="currentColor"