헤더 탭 전환 구조 추가

frontend/public/styles.css

@@ -229,6 +229,55 @@
   background: #f8fafc;
 }
 
+.user-chip {
+  display: inline-flex;
+  align-items: center;
+  gap: 8px;
+  padding: 0 10px;
+}
+
+.user-chip-icon {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  width: 18px;
+  height: 18px;
+  border-radius: 50%;
+  background: #e2e8f0;
+  color: #475569;
+  font-size: 10px;
+  font-weight: 900;
+  flex: 0 0 auto;
+}
+
+.user-chip-text {
+  display: flex;
+  align-items: baseline;
+  gap: 6px;
+  white-space: nowrap;
+}
+
+.user-chip-text strong,
+.user-chip-text em {
+  font-size: 11px;
+  font-style: normal;
+}
+
+.user-chip-text strong {
+  color: var(--color-text);
+}
+
+.user-chip-text em {
+  color: var(--color-text-muted);
+}
+
+.icon-button {
+  width: 34px;
+  padding: 0;
+  justify-content: center;
+  font-size: 13px;
+}
+
 .dashboard-main {
   flex: 1;
   min-height: calc(100vh - 68px);
@@ -254,6 +303,12 @@
   background: #fff;
 }
 
+.stage-empty {
+  flex: 1;
+  min-height: 0;
+  background: transparent;
+}
+
 @media (max-width: 1180px) {
   .dashboard-header {
     grid-template-columns: 1fr;