Serve PDFs locally and automate updates from GitHub

- Add scripts/update-pdfs.js to download latest PDFs - Add cv.pdf and
resume.pdf to public/publications - Update build script to run
update-pdfs before next build - Switch CV and resume URLs to local files
in cv/page.tsx - Add .vercel to .gitignore and vercel.json for
deployment config - Update Next.js to 15.5.2 in package.json and
bun.lock - Update next-env.d.ts and tsconfig.json for new types and
script exclusion

next-env.d.ts

@@ -1,5 +1,6 @@
 /// <reference types="next" />
 /// <reference types="next/image-types/global" />
+/// <reference path="./.next/types/routes.d.ts" />
 
 // NOTE: This file should not be edited
 // see https://nextjs.org/docs/app/api-reference/config/typescript for more information.