A card was detected only with M4ROOT at its root, and asking for two or
more stores returned one too few. A mount point now counts when its root
holds a DCIM or PRIVATE/M4ROOT directory, and the count is exact.
The check and the counting are split from the partition listing so tests
can hand them temporary directories.
Model: opus-5-5
Adopt the standard tooling from sneak/prompts: the Makefile and script/
entrypoints, lint and test stages in one Dockerfile, the lint config, the
CI workflow and the formatter settings. make fmt also formats Go, with a
pinned Go from script/bootstrap. The module path becomes
sneak.berlin/go/dcf.
Fix the lint findings in pkg/dcf. DCFStore becomes Store and DCFObject
becomes Object. Three behaviours change. An error listing mount points is
now returned, where a typo used to drop it. Store.String() prints Store{
instead of DCFStore{, and a negative total as 0 B instead of a huge size.
Replace the placeholder test with real tests. Move the README into the
required sections. make build compiles the library; it pointed at a
command that does not exist.
Model: opus-5-5
Co-authored-by: clawbot <sneak+clawbot@sneak.cloud>