Signals in the needle's orange, and a larger DeadAir tile in the play bar (#268)

Each Signal's tile, icon or initials, is tinted --accent2 in place of
--accent: the orange point of the Signals folder's own icon, so the
folder and what is in it read as one. The player's DeadAir tile goes
from 22px to 26px in its 30px button.

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

docs/signals.md

@@ -20,7 +20,7 @@ their Signals that has not heard about the item yet.
   the set the page's own icons come from: 2,883 icons, solid, regular and brands, searched by name
   and Font Awesome's search terms ("ai" finds the robot). Without one, a Signal shows its initials.
   **Auto** asks Jev to choose (#263), and a Signal made without an icon gets Jev's pick by
-  itself, a moment after it is made. Every Signal's tile is in the accent tint the folder has.
+  itself, a moment after it is made. Every Signal's tile is in the needle's colour (`--accent2`), the orange point of the folder's icon.
 - **Each Signal's row** says "12 items · 3 unread", as a feed's row counts its own.
 - **The folder's page** lists the Signals, as an OPML's page lists its feeds, with the + for a new one.
 - **A Signal's page** is an ordinary item list: All, Unread, Downloaded and Pinned, search and sort.