fix(설정): 357 단축키 칩 글꼴 · 칩만 있는 줄 가로 펼침 · PLAN 357 체크

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013QyNXY2TUKXCFMwAca2APG

A00_Common/app_settings.css

@@ -74,13 +74,17 @@
   gap: var(--spacing-4);
 }
 
+.app-settings__keys:only-child {
+  grid-column: 1 / -1;
+}
+
 .app-settings__keys > kbd {
   padding: 0 var(--spacing-8);
   border: 1px solid var(--color-border);
   border-radius: var(--radius-sm);
   background: var(--color-surface-raised);
   color: var(--color-text);
-  font-family: var(--font-mono);
+  font-family: var(--font-body);
   font-size: 0.85em;
   line-height: 1.7;
 }