Measured on the K2 corpus 2026-09-03: 11 of 39 documents proposed zero
segments -- overwhelmingly PDFs with no declared structure, which Topic 1b
had already measured at 23 of 33. The proposer wrote an artifact for each
of them and exited 0.
An empty plan cannot be replayed. `process_inbox` refuses one by design,
because a plan naming no entry would persist nothing for a document that
was dropped, so the only thing a zero-entry file can do is fail a run
later -- and it did: the first segmented corpus run stopped on
`segmentation_plan_invalid` before writing a single concept.
Exit 1 with no artifact, distinct from 2, so a driver can tell "this
document lands as one flat concept" from "stop". The orphan check's test
now observes the same property through the status.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Kjell Tore Guttormsen
bca722fa85