Fix barely-visible music-note tab icon

The glass-bar redesign dropped the explicit icon color, so inactive
icons fell back to the browser's default text color - fine for icons
that render as full-color emoji, but the music note apparently renders
as a plain glyph on at least one platform, making it nearly invisible
against the bar's near-white glass background. Set it explicitly.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

web/src/components/TabRail.tsx

@@ -60,10 +60,15 @@ export function TabRail({ page, onSelect, showRoom }: Props) {
               border: "none",
               borderRadius: 999,
               background: active ? "var(--accent)" : "transparent",
+              // Explicit, not inherited: at least one of these icons (the music note)
+              // renders as a plain glyph rather than full-color on some platforms, and
+              // without this it fell back to the browser's default text colour - too
+              // close to the glass bar's own near-white background to read.
+              color: active ? "#fff" : "var(--ink)",
               fontSize: 20,
               fontWeight: 900,
               cursor: "pointer",
-              transition: "background 0.15s ease",
+              transition: "background 0.15s ease, color 0.15s ease",
             }}
           >
             {PAGE_ICON[candidate]}