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/app/(public)/layout.tsx

@@ -2,9 +2,9 @@
 
 import Link from 'next/link';
 import { usePathname } from 'next/navigation';
-import { cn } from '@/lib/utils';
-import { useAuthStore } from '@/lib/auth-store';
 import { Button } from '@/components/ui/button';
+import { useAuthStore } from '@/lib/auth-store';
+import { cn } from '@/lib/utils';
 
 export default function PublicLayout({ children }: { children: React.ReactNode }) {
   const pathname = usePathname();