fix: react-doctor → 64/100 (Bugs 122, Perf 286, A11y 613, Maint 436)

- CartContext: lazy initializers replace mount-only useEffect
  hydration; remove 8 no-initialize-state warnings
- Toast/AdminSearchInput: React 19 useContext/use + drop
  forwardRef (3 no-react19-deprecated-apis)
- ProductFormModal: lazy initializers + useSyncExternalStore
  for mount; parent adds key=editingProduct.id
- InstallPrompt: useReducer for prompt state (no-cascading-set-state)
- QRScanModal: ref-based latest-callback pattern replaces
  useEffectEvent deps mistake
- OnboardingFlow: functional setState (rerender-functional-setstate)
- UsersPage/StopsCalendar/FeaturesAndStats: lazy initializers
  (rerender-lazy-state-init)
- FAQClientPage: server-side brand settings fetch via getBrandSettingsPublic
  in layout; remove supabase import
- LandingPageWrapper: href='#' → href='#top' (anchor-is-valid)
- TuxedoVideoHero: replace animate-bounce with ease-out-expo
  (no-inline-bounce-easing)
- ProductTableClient: useCallback for handleDeleted
  (jsx-no-new-function-as-prop)
- excel-parser: pre-compile delimiter regexes (js-hoist-regexp)
- water-log/settings: Promise.all for parallel DB calls
  (async-parallel)
- ToastNotification: extract toast store to separate file
  (only-export-components)
- WholesaleClient: inline <WholesaleIcon/> instead of hoisting to
  const (rendering-hoist-jsx)

src/lib/excel-parser.ts

@@ -68,13 +68,19 @@ export function parseTextBuffer(rawText: string): ParsedSheet {
 
 function detectDelimiter(line: string): string {
   const delimiters = [",", "\t", ";", "|"];
+  // Pre-compile the matcher regexes once so we don't rebuild them on
+  // every loop iteration for every parsed line.
+  const matchers = delimiters.map((d) => new RegExp(`\\${d}`, "g"));
   let best = ",";
   let maxCount = 0;
-  for (const d of delimiters) {
-    const count = (line.match(new RegExp(`\\${d}`, "g")) ?? []).length;
+  for (let i = 0; i < delimiters.length; i++) {
+    // The regex carries the `g` flag, so we need to reset lastIndex
+    // between calls (lastIndex persists on the same regex instance).
+    matchers[i].lastIndex = 0;
+    const count = (line.match(matchers[i]) ?? []).length;
     if (count > maxCount) {
       maxCount = count;
-      best = d;
+      best = delimiters[i];
     }
   }
   return best;