Checkpoint re-hashes all tracked files, stores changed blobs, and
updates per-file timestamps only when content changes. Missing files
are skipped gracefully. Status compares each tracked entry against
the filesystem and reports ok/modified/missing.
CLI: sgard checkpoint [-m message], sgard status.
4 new tests (changed file, unchanged file, missing file, status).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Garden package ties manifest and store together. Supports adding
files (hashed and stored as blobs), directories (manifest-only),
and symlinks (target recorded). Paths under $HOME are stored as
~/... in the manifest for portability. CLI init and add commands
wired up via cobra.
8 tests covering init, open, add for all three entry types,
duplicate rejection, HashFile, and tilde path expansion.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
