This reverts commit 8090d7030984862564a929ee9264e93911014e00.
The cached canonical field was optimizing an unmeasured path: without
the (deferred) O(closure) dependency re-validation multiplier, the
repeated serialization is microseconds for realistic versions. Compute
canonical bytes on demand like the environment, automation, and MCP
stores do, rather than carrying a serde-skipped cache field, a
construction bootstrap, and doubled memory for it. Purely in-memory:
stored blobs and version IDs are unchanged.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>