Updates UI arrows to match look and feel

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017DUU6CnxECCDeqDNYJgr5x

src/components/common/Chevron.tsx

@@ -0,0 +1,16 @@
+/** Thin-stroke disclosure chevron, rotating in place to point down when
+ *  expanded. A crisp line icon reads much more consistent with the rest of
+ *  the UI's small action glyphs (✕ ✎ ⧉ +) than a filled unicode triangle,
+ *  which looks bold/blocky and doesn't align cleanly at small sizes. */
+export default function Chevron({ expanded, className = '' }: { expanded: boolean; className?: string }) {
+  return (
+    <svg
+      viewBox="0 0 20 20"
+      fill="none"
+      aria-hidden="true"
+      className={`h-3 w-3 shrink-0 transition-transform duration-150 ${expanded ? 'rotate-90' : ''} ${className}`}
+    >
+      <path d="M7 4l6 6-6 6" stroke="currentColor" strokeWidth={2} strokeLinecap="round" strokeLinejoin="round" />
+    </svg>
+  )
+}