treefmt: apply prettier

Pure `nix fmt` output from the commit before this one — no hand edits.
203 files: 52 md, 42 tsx, 32 js, 32 css, 21 ts, 13 html, 8 json, 3 mjs.

Reproduce with `nix develop -c nix fmt` on the parent commit; the result
should be byte-identical to this tree.

None of the 13 `.prettierignore` entries appears here — verified by
intersecting the changed-file list against the ignore file, with a
control proving the intersection finds a match when one exists.

frontend/packages/shared/src/theme.css

@@ -29,9 +29,21 @@
      a swap. Each is pixel-identical to its prior literal under the
      default palette: --crust is a darkened bg; --muted / --subtext0 are
      foreground↔background blends (two levels of dimmed text). */
-  --crust: color-mix(in srgb, var(--base00) 58%, #000000); /* terminal / code bg, below --bg */
-  --muted: color-mix(in srgb, var(--base05) 55.5%, var(--base00)); /* secondary / dimmed text */
-  --subtext0: color-mix(in srgb, var(--base05) 77.7%, var(--base00)); /* toolbar/status text; dimmer than --fg, lighter than --muted */
+  --crust: color-mix(
+    in srgb,
+    var(--base00) 58%,
+    #000000
+  ); /* terminal / code bg, below --bg */
+  --muted: color-mix(
+    in srgb,
+    var(--base05) 55.5%,
+    var(--base00)
+  ); /* secondary / dimmed text */
+  --subtext0: color-mix(
+    in srgb,
+    var(--base05) 77.7%,
+    var(--base00)
+  ); /* toolbar/status text; dimmer than --fg, lighter than --muted */
 
   /* `--muted`, above, is mixed toward `--base00`/`--bg` — correct for
      dimmed text on the page background, wrong for dimmed text sitting on