fix: use plain CSS class for pill font size instead of Tailwind token

The @theme --text-pill token and text-[8px] arbitrary value both
failed to apply at dev time due to @tailwindcss/vite not generating
the utility rule during HMR. Use a plain .pill-trigger CSS class
in styles.css instead, which is always available regardless of
Tailwind's JIT scanner behavior.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/renderer/styles.css

@@ -10,8 +10,6 @@
   --color-accent: #6366f1;
   --color-accent-hover: #818cf8;
   --color-accent-muted: rgba(99, 102, 241, 0.15);
-  --text-pill: 0.5rem;
-  --text-pill--line-height: 1;
 }
 
 :root {
@@ -28,6 +26,13 @@
   -moz-osx-font-smoothing: grayscale;
 }
 
+/* ── Inline pill trigger buttons ────────────────────────────── */
+
+.pill-trigger {
+  font-size: 0.5rem;
+  line-height: 1;
+}
+
 /* ── Light mode colour overrides ────────────────────────────── */
 
 [data-theme="light"] {