Hand mark_done! the digest save! just returned

[sotashimozono]

Closes #58.

save! returns (; file, sha256) naming the bytes it wrote. mark_done! takes result= and writes result_sha256 / result_file / observation from it. The call between the two threw the value away:

DataVault.save!(vault, key, payload)
DataVault.mark_done!(vault, key)

So every sweep this runner has driven wrote a .done that says unknown, and no run it produced can state that what a reader loads is what the computation wrote.

What it cost

Both ends of the chain were already built and only the middle did not pass the value along. Pinax.report hashes each result as it reads it; Archeion.provenance_from compares that against the recorded digest. Measured on a deposited revision of a real study:

[counts]
read_differs_from_result = 0
read_matches_result      = 0
result_unknown           = 12

Twelve points read and hashed, and nothing to check them against. The catalogue page built from that revision says it out loud — "read 12 points: 0 read as recorded · 12 unrecorded" — which is honest and useless. And capability.verified with criterion result-file-sha256 (Archeion SPEC §6), the event by which a revision earns the claim that it can be recomputed, cannot be earned at all while the digest is missing.

The change

saved = DataVault.save!(vault, key, payload)
DataVault.mark_done!(vault, key; result=saved)

[compat] DataVault moves to 0.8.5, where mark_done!(; result) and done_version=2 arrived — the old "0.7, 0.8" admitted versions with no such keyword, and this environment was in fact resolving 0.7.8.

The test

Written from the consumer's side, through load_recorded, because that is who suffers: nothing inside the runner notices a missing digest — the sweep succeeds, every key is :done, and only a reader two packages away can tell. It checks three things:

• the digest is present and done_version == "2";
• it is the digest of the file — read_sha256 == result_sha256, so a plausible-looking hash of the wrong bytes fails;
• a result replaced behind the runner's back makes the two differ, which is the comparison this restores.

Verified to fail without the fix (both assertions, on every key) and pass with it: 25 tests.

What this does not do

Existing .done files cannot be repaired. A digest computed now would name today's bytes while claiming the computation recorded them — a worse record than unknown.

🤖 Generated with Claude Code

[sotashimozono]

Superseded: main already passes save!'s digest to mark_done! (#54, 06b38d5). Since #61 it does so through the owner-checked form, mark_done!(vault, key, tok; result=saved, observation=…). This branch is based on 0.6.2, and its remaining changes are formatting.