Wraps pure (query/transform) atom invocations with SHA-256 keyed
cache. Refuses Command/Stream kind atoms as unsafe.
22/22 tests (14 unit + 8 integration). Canonical JSON keying
(formatting-drift safe). TTL expiry. AtomExecutor trait decouples
subprocess from test mocks.
Default DB ~/.claude/cache/cache.sqlite, overridable via --db or
$KEI_CACHE_DB.
Workspace Cargo.toml: +kei-cache member.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
