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/routes/admin/sessions.ts

@@ -1,12 +1,8 @@
 import { FastifyInstance } from "fastify";
-import crypto from "crypto";
 import prisma from "../../config/database";
 import { requireAuth } from "../../middleware/auth";
 import { success, error } from "../../utils/response";
-
-function hashToken(token: string): string {
-  return crypto.createHash("sha256").update(token).digest("hex");
-}
+import { hashToken } from "../../services/auth";
 
 /** Parse user-agent string into browser, OS, and device icon */
 function parseUserAgent(ua: string | null): {