UI: refresh dashboard design system

- Typography: swap Inter for Space Grotesk (geometric, techy)
- Colors: punchier accent red, add teal secondary, warmer darks
- Cards: better shadows, hover lift effect, increased padding
- Stats: uppercase labels, larger bold values
- Buttons: hover lift micro-interaction, glow on primary
- Status dots: glow effects and subtle pulse animation
- Callouts: gradient backgrounds for depth
- Navigation: active state accent bar indicator
- Layout: more breathing room, bolder page titles

ui/src/styles/layout.css

@@ -404,6 +404,7 @@
 .nav-item.active {
   color: var(--text-strong);
   background: var(--accent-subtle);
+  border-color: rgba(255, 92, 92, 0.15);
 }
 
 .nav-item.active .nav-item__icon {
@@ -411,6 +412,18 @@
   color: var(--accent);
 }
 
+.nav-item.active::before {
+  content: '';
+  position: absolute;
+  left: 0;
+  top: 50%;
+  transform: translateY(-50%);
+  width: 3px;
+  height: 16px;
+  background: var(--accent);
+  border-radius: 0 2px 2px 0;
+}
+
 /* ===========================================
    Content Area
    =========================================== */