fix: production readiness — resolve build, lint, and code quality issues

- Fix Next.js build failure: remove duplicate route at (dashboard)/listings/[id]
  that conflicted with (public)/listings/[id] (same URL path in two route groups)
- Fix 772 ESLint errors: auto-fix import ordering (import-x/order), remove unused
  imports/variables, convert empty interfaces to type aliases, replace require()
  with ESM imports, fix consistent-type-imports violations
- Add CLAUDE.md for developer onboarding documentation
- All checks pass: 0 lint errors, typecheck clean, 230 tests passing, build success

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

apps/web/components/map/listing-map.tsx

@@ -1,9 +1,8 @@
 'use client';
 
-import * as React from 'react';
 import mapboxgl from 'mapbox-gl';
+import * as React from 'react';
 import 'mapbox-gl/dist/mapbox-gl.css';
-import { Badge } from '@/components/ui/badge';
 import type { ListingDetail } from '@/lib/listings-api';
 
 function formatPrice(priceVND: string): string {