fix(M02): 층 단추 눌린 표시 · 한 줄 폭 맞춤, 프로젝트 기본값은 마지막 고른 것 → 내 최근 것 → 빈 칸

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0148XFUpPfpiuTjxF1EK9c95

M02_MasterTemplete/M02_MasterTemplete_UI_Style.css

@@ -8,13 +8,19 @@
 
 .m02-side__layers {
   display: grid;
-  grid-template-columns: repeat(4, 1fr);
+  grid-template-columns: repeat(auto-fit, minmax(72px, 1fr));
   gap: var(--spacing-4);
 }
 
+.m02-side__layers .ui-btn {
+  padding-inline: var(--spacing-4);
+  white-space: nowrap;
+}
+
 .m02-side__layers .ui-btn.is-active {
+  background: var(--color-accent);
   border-color: var(--color-accent);
-  color: var(--color-accent);
+  color: var(--color-on-accent, #fff);
   font-weight: var(--font-weight-bold);
 }