A second substrate validating the contract beyond plain folders: a git-IS-store
shard reading Markdown from a git repo. Keys are tracked *.md paths; read returns
a Page whose source_rev is the per-path last-commit sha (so an edit to one page
never drifts another); profile is git-IS-store / substrate=git / history=git-native
/ addressing=path, validated against the §6.5 implication rules. Passes the
conformance read path with honest absence of unclaimed verbs. Zero new deps
(git CLI via subprocess). No core changes.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
