Project layout

From snippets to a service

Everything so far lived in one main.go scratch file. A real backend doesn't. PawWalk will grow walkers, bookings, GPS, auth, and tests — so we lay it out the way every production Go service is laid out, right now, before the code piles up.

Go has a strong community convention for this. It's not enforced by the compiler (except one rule we'll meet in a moment), but every Go engineer recognizes it on sight: