Rewrite createMemoryStore() to return an OcasStore with three sub-stores:
cas, var, tag. The cas sub-store keeps the existing Map-based logic, but
its put is now synchronous; the in-memory VarStore and TagStore are new
Map-based implementations of the types defined in #39.
The legacy Store.put signature is widened to Hash | Promise<Hash> so that
the new sync cas can still be passed to helpers (bootstrap, gc, render,
schema, …) that have not yet been migrated to the unified surface.
Tests in packages/core were mechanically updated from store.* to
store.cas.* and new test suites for VarStore (var-store.test.ts) and
TagStore (tag-store.test.ts) cover the spec from issue #40.
Closes#40
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
xiaoju