CI build of golang:1.25-alpine ships go 1.25.10; auto-generated
go.mod had 1.26.3 from local toolchain. Use 1.25 to match the other
automc services (auth-service, server-manager etc all on 1.25).
HTTP API + on-disk storage + auth-service token verification + dev mode.
31 tests pass, vet clean. See DESIGN.md for the architecture and
README.md for the operator surface.
Pending: pg-backed per-user quota override, snapshot retention / blob GC,
tarball-vs-manifest content cross-check, end-to-end deploy on john.