refactor: fix all Low findings from FLAWS_REPORT audit

- Auth: TOTP params from config, JWT error logging, audit log failure
  logging, replaced_by_hash validation on token rotation
- Invoices: remove dead VAT code, consistent PDF permissions,
  WebP magic-byte detection, deduped exchange-rate fetches
- Orders/Offers: multipart limit from config, use paginated() helper,
  payment method from DB in PDF
- Projects: verify project exists before creating note
- Attendance: action_type enum validation, consistent local-time
  shift_date construction, holiday attendance in work fund,
  trips.view permission on last-km query
- Users: paginated() helper usage, remove duplicate dashboard keys,
  parallel currency conversion, single hashToken implementation
- Frontend: memoized customInput, reliable print onload, modal prop
  standardization (isOpen), ConfirmModal type icons, id===0 key
  fallback, Login useCallback, CompanySettings ConfirmModal,
  Attendance timeout cleanup, Dashboard memoization, beforeunload
  dirty-state warnings on Invoice/Offer/Order detail
- Schema: invoice_alert_log timestamp, config/env comment on
  Date.prototype.toJSON override
- Utils: exchange-rate inflight dedup

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/admin/pages/Dashboard.tsx

@@ -129,7 +129,7 @@ export default function Dashboard() {
   }, [fetch2FAStatus]);
 
   // Punch (prichod/odchod) primo z dashboardu
-  const handleQuickPunch = () => {
+  const handleQuickPunch = useCallback(() => {
     const action = dashData?.my_shift?.has_ongoing ? "departure" : "arrival";
     setPunching(true);
 
@@ -167,7 +167,7 @@ export default function Dashboard() {
       () => submitPunch({}),
       { enableHighAccuracy: true, timeout: 10000, maximumAge: 60000 },
     );
-  };
+  }, [dashData, alert, fetchDashboard]);
 
   // 2FA handlery
   const handleStart2FASetup = async () => {