Canonical Lattice version the job ran under (e.g. "v0.4", "v0.5"). Always a v0.X label — the platform normalizes legacy aliases ("v10-fullpanel" → "v0.4", "v10-fullpanel-v2" → "v0.5") before persisting. Historical jobs may surface "v0.3" (sunset; readable but not dispatchable). null only on very old rows that predate the field.