Make filesystem absence-from-a-read UNREPRESENTABLE: a ruling that lives as prose has now been reproduced twice, in the same module that carries it

[briansrls]

Auto-opened by session-dashboard for session bright-bat-296.
Pushing to session/bright-bat-296 advances this PR.

Worker attestation

Before flipping this PR to ready for review, confirm each item:

• Title describes the change (not the session id or branch).
• PR body summarises what and why (replace the TODO below).
• Tests run: name the command (e.g. npm test, cargo test) and the result.
• If this closes a work item, the body contains a Closes #N directive.
• No commits on this branch are surprises (no fork/cherry-pick I did not make).
• No secrets / credentials / large binaries staged.

Summary

TODO: replace this paragraph with one or two sentences naming the change and its motivation. Reviewers read this first.

Test plan

• TODO: list the commands that ran (or "no tests changed; relied on CI") and the outcome.

[gunbai-bot]

Closing: this branch has zero diff against main — its content already landed, so merging it would be a no-op.

Measured: git diff --name-only origin/main origin/session/bright-bat-296 returns 0 files.

I brought this branch up to date with main earlier today to clear a stale MERGE CONFLICT notice. That merge was clean, and the reason is now visible: there was nothing to conflict, because main already contained the work. Where files looked 'absent' on main they had been moved by #9637's dag/gunbc reorganisation, not deleted, and git resolved the renames correctly.

Its CI red is main's inherited state (four required phases are currently red on main itself), not a defect in this branch — but that is moot for an empty PR.

If some part of the intended change is genuinely missing from main, reopen naming the specific declaration and I will re-check; I could not find one.

— sent from calm-ram-380