fix: 2026-06-09 full-codebase audit hardening

Validation: shared NaN-guarded Zod coercion helpers in schemas/common.ts replace
the raw number|string transform idiom across every schema (the root-cause NaN bug
class); emailOrEmpty + lenient isoDateString/timeString.

Security: roles privilege-escalation closed; refresh-token family revocation on
reuse; TOTP uses config params; read endpoints permission-guarded; received-invoices
gross VAT on all paths; orders-pdf custom-items authz.

Concurrency: $queryRaw SELECT...FOR UPDATE locks in ascending-id order (warehouse
confirm/cancel, attendance lockUserRow); uniqueness checks moved into create
transactions (TOCTOU -> 409); deterministic id tiebreak on second-precision
timestamp ordering (plan resolveCell/resolveGrid, warehouse FIFO).

Frontend: Rules-of-Hooks fixed across ~14 pages + PlanCellModal; UTC-date persisted
fields; dashboard invalidation gaps; stale-closure confirm bugs.

Tooling/tests: ESLint flat config (react-hooks/rules-of-hooks = error) + Prettier;
tsconfig.test.json so tsc -b type-checks the tests; removed 3 dead deps; npm audit
fix (8 -> 3). Suite 195 -> 247 (happy-path auth, FIFO oldest-first, flakiness fixes),
isolated on app_test via .env.test with a hard-throw setup guard.

Gates: tsc 0 | build 0 | vitest 247/247 | eslint 0 errors.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/admin/ui/Modal.tsx

@@ -46,15 +46,22 @@ export default function Modal({
   // title/submitText NOR the loading state flips during the close fade-out
   // (e.g. on save, `loading` goes false a beat before the dialog finishes
   // closing — without this the button would flash back to "Uložit změny").
-  const [shown, setShown] = useState({ title, subtitle, submitText, loading });
+  const [shown, setShown] = useState({
+    title,
+    subtitle,
+    submitText,
+    cancelText,
+    loading,
+  });
   if (
     isOpen &&
     (shown.title !== title ||
       shown.subtitle !== subtitle ||
       shown.submitText !== submitText ||
+      shown.cancelText !== cancelText ||
       shown.loading !== loading)
   ) {
-    setShown({ title, subtitle, submitText, loading });
+    setShown({ title, subtitle, submitText, cancelText, loading });
   }
 
   return (
@@ -78,7 +85,7 @@ export default function Modal({
       <DialogActions sx={{ px: 3, pb: 2 }}>
         {!hideCancel && (
           <MuiButton onClick={onClose} color="inherit" disabled={shown.loading}>
-            {cancelText}
+            {shown.cancelText}
           </MuiButton>
         )}
         <MuiButton