fix: resolve react-doctor errors (hooks order, reduced motion, key prop) (#105)

- Move useCallback hooks before early return in ReferencesDialog
  to fix conditional hook call violation (Rules of Hooks)
- Add useReducedMotion hook and apply to all motion animations
  for WCAG 2.3.3 accessibility compliance
- Replace useEffect state reset with key prop on ItemCatalog
  for proper React reconciliation on category change
- Add global prefers-reduced-motion CSS media query

Fixes 4 react-doctor errors, bringing score from 81 to ~85+.

apps/editor/app/globals.css

@@ -144,3 +144,14 @@
   -ms-overflow-style: none; /* IE and Edge */
   scrollbar-width: none; /* Firefox */
 }
+
+@media (prefers-reduced-motion: reduce) {
+  *,
+  *::before,
+  *::after {
+    animation-duration: 0.01ms !important;
+    animation-iteration-count: 1 !important;
+    transition-duration: 0.01ms !important;
+    scroll-behavior: auto !important;
+  }
+}