⚡ Bolt: Optimize category and profile derivation with single loop

.jules/bolt.md

@@ -5,3 +5,7 @@
 ## 2025-03-09 - Replace .map() with point updates for React state arrays
 **Learning:** For updating single items in small React state arrays (e.g., layout configurations or task lists), using `array.map()` introduces significant performance overhead by iterating through the entire array and calling the callback for every element. This causes unnecessary processing.
 **Action:** Prefer "point updates" using `findIndex` and array spreading over `array.map()`. This minimizes object allocations and improves fluidity, especially on lower-power devices.
+
+## 2025-03-09 - Consolidate Multiple Array Iterations into Single Loop for Derived React State
+**Learning:** When deriving multiple unique sets of data from a single large source array (like categories and profiles from a shortcuts list), using separate `useMemo` hooks with chained declarative array methods (`map`, `flatMap`, `Set`) results in multiple unnecessary iterations over the entire dataset and intermediate array allocations. This scales poorly with large arrays.
+**Action:** Consolidate the calculations into a single `useMemo` hook and use a single imperative `for` loop to populate multiple `Set`s simultaneously. This reduces iteration count and memory overhead, yielding significant performance gains on large datasets.

components/CategoryFilterWidget.tsx

@@ -6,12 +6,24 @@ import { UsersIcon } from '@heroicons/react/24/outline';
 export const CategoryFilterWidget: React.FC = () => {
   const { shortcuts, filterCategory, setFilterCategory, filterProfile, setFilterProfile } = useGTab();
 
-  const activeCategories = useMemo(() => {
-    return ['All', ...new Set(shortcuts.map(s => s.category))];
-  }, [shortcuts]);
+  const { activeCategories, uniqueProfiles } = useMemo(() => {
+    const categories = new Set<string>();
+    const profiles = new Set<string>();
+
+    for (let i = 0; i < shortcuts.length; i++) {
+      const s = shortcuts[i];
+      if (s.category) categories.add(s.category);
+      if (s.profiles) {
+        for (let j = 0; j < s.profiles.length; j++) {
+          profiles.add(s.profiles[j].name);
+        }
+      }
+    }
 
-  const uniqueProfiles = useMemo(() => {
-    return Array.from(new Set(shortcuts.flatMap(s => s.profiles?.map(p => p.name) || []))).sort();
+    return {
+      activeCategories: ['All', ...categories],
+      uniqueProfiles: Array.from(profiles).sort()
+    };
   }, [shortcuts]);
 
   return (