security: fix all Medium findings from FLAWS_REPORT audit

- Auth: TOTP replay protection with counter tracking, constant-time
  backup code comparison, atomic lockout increment, per-token logout
- Invoices/PDFs: net-based VAT calculation, dangerous URL scheme
  stripping in cleanQuillHtml, orders-pdf error handling
- Orders: reject item changes on status transition, cascading
  delete cleanup, take:1 with orderBy
- Projects: atomic rename collision handling, MIME/extension
  validation, empty customer name rejection
- Attendance: Czech public holiday awareness in frontend fund
  calculation, leave_hours 0 handling, invalid date NaN guard,
  bounded per-month queries in workfund
- Users/Admin: profile audit logging + password validation, session
  revocation guard, session ID validation, dashboard DB aggregation,
  soft-deleted record protection in scope templates
- Frontend: FormField label linkage, Pagination ARIA, error
  handling in OrderConfirmationModal, 401 propagation, GPS emoji
  hidden from screen readers, table sort state fix, geolocation
  race/abort cleanup, Leaflet popup DOM safety, Vehicles toggleActive
  minimal body, CompanySettings ref mutation fix, OfferDetail unlock
  abort, AttendanceBalances combined fetches
- Utils: env validation, Puppeteer concurrency mutex, invoice alert
  cron cleanup on shutdown, body limit alignment, TOTP error logging,
  trustProxy from env, symlink rejection, rate cache Map usage

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

src/admin/components/Pagination.tsx

@@ -36,13 +36,18 @@ export default function Pagination({
   };
 
   return (
-    <div className="admin-pagination">
+    <div
+      className="admin-pagination"
+      role="navigation"
+      aria-label="Stránkování"
+    >
       <div className="admin-pagination-info">{total} záznamů</div>
       <div className="admin-pagination-controls">
         <button
           disabled={page <= 1}
           onClick={() => onPageChange(page - 1)}
           className="admin-pagination-page"
+          aria-label="Předchozí stránka"
         >
           <svg
             width="16"
@@ -65,6 +70,8 @@ export default function Pagination({
               key={p}
               onClick={() => onPageChange(p)}
               className={`admin-pagination-page ${p === page ? "active" : ""}`}
+              aria-label={`Stránka ${p}`}
+              aria-current={p === page ? "page" : undefined}
             >
               {p}
             </button>
@@ -74,6 +81,7 @@ export default function Pagination({
           disabled={page >= total_pages}
           onClick={() => onPageChange(page + 1)}
           className="admin-pagination-page"
+          aria-label="Další stránka"
         >
           <svg
             width="16"