Static files are now compiled into the binary using //go:embed.
- Add web/embed.go with //go:embed static directive
- Update server.New() to accept fs.FS parameter
- Switch file server from http.Dir to http.FS

Deployment is now: roadamp.exe + config.yaml + winamp/

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>