feat(admin): group navigation into media, uploads and system

apps/web/src/widgets/AppShell.module.css

@@ -170,6 +170,22 @@
   display: none;
 }
 
+.navSubsection {
+  min-height: 40px;
+  margin: 2px 0;
+  font-size: 13px;
+  font-weight: 600;
+  letter-spacing: normal;
+  text-transform: none;
+  color: var(--text2);
+}
+
+.navSubgroup > .navItem {
+  margin-left: 12px;
+  padding-left: 12px;
+  border-left: 1px solid var(--line);
+}
+
 .navItem {
   display: flex;
   align-items: center;
@@ -295,6 +311,9 @@
   .navGroupFolded {
     display: contents;
   }
+
+  .navSubsection { min-height: 0; }
+  .navSubgroup > .navItem { margin-left: 0; padding-left: 0; border-left: 0; }
 }
 
 .mobileBottom { display: none; }
@@ -358,6 +377,8 @@
     border: 0; pointer-events: none;
   }
   .mobileMenu .navSectionTitle { display: block; }
+  .mobileMenu .navSubsection { color: var(--text2); font-size: 13px; }
+  .mobileMenu .navSubgroup > .navItem { margin-left: 12px; border-left: 1px solid var(--line); }
   .mobileMenu .navChevron { display: none; }
   .content, .island .content { padding: 20px 16px 24px; }
 }