File Uploads

Handles the full stack of file uploads from client to cloud storage, with a focus on S3 and Cloudflare R2. You'll want this when you're dealing with presigned URLs, multipart uploads for large files, or image optimization pipelines. The sharp edges table is the real value here: it calls out the critical security mistakes like trusting file extensions instead of checking magic bytes, and warns against path traversal via unsanitized filenames. It's opinionated about keeping uploads off your main server and using presigned URLs instead of proxying, which is the right call for anything handling real traffic.