List images without header channel names in a described run (follow-up of #218) #225

In a run with a published description, the P26 per-unit header checks (#218, physical_check.py, run/description_run.py) let an image whose header gives no channel names pass (Spec §4.3, fixture v12: it needs no evidence, the user's confirmed layout is used). Nothing says afterwards which images stood on that confirmation alone.

Owner decision (2026-11-08)

Keep such images passing, but list them:

• record them in the run manifest's experiment_description entry: per unit, the images with no header channel names and, for partially named images, which channel positions had no name;
• show them in the report text;
• no warning;
• undescribed runs unchanged (the v0.4.0 parity suite must pass; no new manifest key there);
• the manifest field is read back strictly by read_manifest; RunInputs may expose it read-only if cheap.

Acceptance

• A described run with one unnamed-header image and one partially named image records exactly those, round-trips through read_manifest, and shows in the report text.
• A fully named run records no list (key omitted, documented).
• An undescribed run has no new key.