security: fix all Critical and High findings from FLAWS_REPORT audit

- Auth: pessimistic locking on login tokens and refresh token rotation,
  backup code attempt counter, rate limiting verification
- Schema: unique constraints on business numbers, FK relations,
  unsigned/signed alignment, attendance duplicate prevention
- Invoices/PDFs: DOMPurify sanitization, bounded queries in stats
  and alerts, VAT rounding, Puppeteer error handling
- Orders/Offers: transactional parent+child creation, Zod NaN
  refinement, status enums, uniqueness checks
- Projects/Files: path traversal protection, streamed uploads,
  permission guards, query param validation
- Attendance/HR: duplicate checks, ownership validation, GPS
  restrictions, trip distance validation
- Frontend: modal lock reference counting, XSS escaping in print
  HTML, ref mutation fixes, accessibility attributes

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

src/admin/components/ProjectFileManager.tsx

@@ -197,6 +197,7 @@ export default function ProjectFileManager({
 }: ProjectFileManagerProps) {
   const alert = useAlert();
   const fileInputRef = useRef<HTMLInputElement>(null);
+  const isCancelling = useRef(false);
 
   const [items, setItems] = useState<FileItem[]>([]);
   const [loading, setLoading] = useState(true);
@@ -768,10 +769,26 @@ export default function ProjectFileManager({
                             }}
                             autoFocus
                             onKeyDown={(e) => {
-                              if (e.key === "Enter") handleRename(item);
-                              if (e.key === "Escape") setRenamingItem(null);
+                              if (e.key === "Enter") {
+                                e.preventDefault();
+                                handleRename(item);
+                              }
+                              if (e.key === "Escape") {
+                                e.preventDefault();
+                                isCancelling.current = true;
+                                setRenamingItem(null);
+                                setRenameValue(item.name);
+                                setTimeout(() => {
+                                  isCancelling.current = false;
+                                }, 0);
+                              }
+                            }}
+                            onBlur={() => {
+                              if (isCancelling.current) {
+                                return;
+                              }
+                              handleRename(item);
                             }}
-                            onBlur={() => handleRename(item)}
                           />
                         ) : (
                           <FileNameCell