- CAS: GET /files/{hash} with immutable cache headers, launcher asset
serving, hash validation, StoreFile/VerifyAndStore helpers
- Middleware: CORS, request logging, per-IP token bucket rate limiter
- Utils: SHA1Bytes, SHA256Bytes, SHA1File, Unzip with zip-slip protection
- Templates: placeholder handler with html/template discovery
- Wire CAS routes and middleware chain (Logging → CORS) in main.go