First scan runs one exiftool process per file and blocks startup #4

format.Magick.Metadata spawns exiftool per file, and cmd/gallery/main.go runs the first Scan before ListenAndServe. A library of a few thousand photos keeps the site down for minutes on first boot.

Options: exiftool -stay_open True -@ - with a long-lived process, or batch many files per invocation (exiftool -json file1 file2 ...); start serving before the first scan finishes.