feat: separate codex live and automation context

src/app/main/MainLayout.css

@@ -174,10 +174,23 @@
   gap: 8px;
 }
 
+.app-header__settings-group {
+  display: flex;
+  flex-direction: column;
+  gap: 6px;
+}
+
 .app-header__settings-item:hover {
   background: #f3f7ff;
 }
 
+.app-header__settings-item--nested {
+  margin-left: 12px;
+  min-width: 0;
+  padding-left: 14px;
+  background: #f8fbff;
+}
+
 .app-header__settings-icon {
   position: relative;
   display: inline-flex;
@@ -241,10 +254,23 @@
 }
 
 .app-header__settings-label {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  flex: 1;
   font-size: 14px;
   font-weight: 600;
 }
 
+.app-header__settings-group-arrow {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  width: 16px;
+  color: #64748b;
+  font-size: 12px;
+}
+
 .app-header__update-progress {
   display: flex;
   flex-direction: column;