feat: add MFA/TOTP auth, PII encryption, agents/leads/inquiries modules, and comprehensive tests

- Add TOTP-based MFA with setup, verify, disable, backup codes, and challenge flow
- Add PII field encryption middleware with AES-256-GCM and deterministic search hashes
- Add agents, inquiries, and leads domain modules with entities, events, value objects
- Add web dashboard pages for inquiries and leads with detail dialogs
- Add 30+ component tests (valuation, charts, listings, search, providers, UI)
- Add Prisma migrations for encryption hash columns and MFA TOTP support
- Fix all ESLint errors (unused imports, duplicate imports, lint auto-fixes)
- Update dependencies and lock file
- Clean up obsolete exploration/QA docs, add audit documentation

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/web/messages/en.json

@@ -36,6 +36,8 @@
     "title": "Dashboard",
     "listings": "Listings",
     "createListing": "Create listing",
+    "inquiries": "Inquiries",
+    "leads": "Leads",
     "analytics": "Analytics",
     "savedSearches": "Saved searches",
     "aiValuation": "AI Valuation",

apps/web/messages/vi.json

@@ -36,6 +36,8 @@
     "title": "Bảng điều khiển",
     "listings": "Tin đăng",
     "createListing": "Đăng tin",
+    "inquiries": "Liên hệ",
+    "leads": "Lead",
     "analytics": "Phân tích",
     "savedSearches": "Tìm kiếm đã lưu",
     "aiValuation": "Định giá AI",