Toggles show their state the same way everywhere (#74, #75)

A sweep of all 24 theme palettes, measuring each icon's drawn colour,
found pinned in three colours: accent in the feed list, the text colour
on an item's row, and uncoloured on the toolbar, beside the title and on
the feed page. The read button showed the action (an envelope on a read
item) beside a pin showing the state. Now each toggle shows what is, with
aria-pressed, and a pressed one is the accent colour; Classic needs its
own rule, as its buttons set their colour at higher specificity. The
contrast test checks the accent on the button grounds, where it now draws.

Directory's Subscribe button carried the Subscribed tick; it is a plus.

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

tests/contrast.js

@@ -27,6 +27,7 @@ const RULES = [
   ['dim', ['bg', 'panel', 'panel2'], 4.5],       // metadata, labels
   ['faint', ['bg', 'panel', 'panel2'], 4.5],     // hints, column headings, the status bar
   ['accent', ['bg', 'panel'], 4.5],              // links, in the list and the reader
+  ['accent', ['panel2', 'raise'], 3],            // a toggle that is on: pinned, read
   ['ink', ['accent'], 4.5],                      // a primary button's label
   ['ink', ['accent2'], 4.5],                     // the unread count on its badge
   ['accent2', ['bg', 'panel', 'raise'], 3],      // the unread dot, the EQ bars, download bars