feat(ui): Redesign sidebar, one-touch toggles, fix trash & subtask optimistic UI, auto-admin, and full n-depth DND

src/app/globals.css

@@ -459,9 +459,30 @@ a { color: inherit; text-decoration: none; }
   color: var(--accent);
 }
 
+.sidebar {
+  width: var(--sidebar-w, var(--sidebar-width));
+  min-width: var(--sidebar-w, var(--sidebar-width));
+  background: var(--bg-secondary);
+  border-right: 1px solid var(--border);
+  display: flex;
+  flex-direction: column;
+  height: 100%;
+  overflow: hidden;
+  position: relative;
+  transition: width var(--dur-normal) var(--ease-out);
+}
+
+.sidebar-search-box:hover {
+  border-color: var(--accent) !important;
+  background: var(--bg-primary) !important;
+  box-shadow: 0 0 0 2px var(--accent-light);
+}
+
 .sidebar-footer {
+  margin-top: auto;
   padding: 8px 8px 12px;
   border-top: 1px solid var(--border);
+  background: var(--bg-secondary);
 }
 
 .user-card {
@@ -471,10 +492,15 @@ a { color: inherit; text-decoration: none; }
   padding: 8px 10px;
   border-radius: var(--radius-sm);
   cursor: pointer;
-  transition: background var(--dur-fast);
+  transition: all 0.15s cubic-bezier(0.16, 1, 0.3, 1);
+  border: 1px solid transparent;
 }
 
-.user-card:hover { background: var(--bg-hover); }
+.user-card:hover {
+  background: var(--bg-primary);
+  border-color: var(--border);
+  box-shadow: var(--shadow-xs);
+}
 
 .user-avatar {
   width: 32px;