[Tool] Add File Storage / CDN category

[Surfrrosa]

What's Missing

We don't have a File Storage / CDN category yet. This comes up constantly for solo founders building image-heavy or file-heavy products.

Tools to Research and Add

• Cloudflare R2 -- S3-compatible object storage with zero egress fees. This is the big story in 2026.
• Uploadthing -- Developer-focused file uploads, built for Next.js.
• Bunny CDN -- Simple, affordable CDN for static assets.
• AWS S3 -- The graduation path. Industry standard.

What to Do

1. Create a YAML file for each tool in data/tools/ following the YAML schema
2. Add a collapsible "File Storage / CDN" section to the Tool Directory in README.md
3. Verify all pricing data and include last_verified dates

Helpful Links

• CONTRIBUTING.md for the YAML schema and quality standards
• Look at existing files in data/tools/ for reference

This is a great first contribution -- each tool file is self-contained and follows a clear template.