Redesign ticket list to three-column layout with proportional widths

- Replace Sheet slide-over with inline peer detail column
- List column: 40% width (min 360px) when ticket selected, flex-1 otherwise
- Detail column: 60% width (min 480px), slides in from right (300ms)
- Mobile: list hidden when ticket selected, detail becomes full-width
- Subtle border-r divider on list column
- Taller ticket rows (py-4) with smooth hover transitions
- width transition on list column resize

web/src/app/globals.css

@@ -117,6 +117,17 @@
   --sidebar-ring: oklch(0.556 0 0);
 }
 
+@keyframes slide-in-right {
+  from {
+    transform: translateX(100%);
+    opacity: 0;
+  }
+  to {
+    transform: translateX(0);
+    opacity: 1;
+  }
+}
+
 @layer base {
   * {
     @apply border-border outline-ring/50;