Under the hood
Artifact ref resolution no longer fails outright when a read version is missing for an attached frame
What
The internal helper that resolves an artifact's current frame URL and version, used when cross-referencing artifact reads, used to return nothing whenever a read version was missing. Now it only returns nothing in that case if the matching frame's key doesn't start with the "attached:" prefix; otherwise it returns the reference without a version field.
Why
This lets artifact references for attached frames still resolve even when no read version is recorded for them, instead of being dropped entirely.