Freeze the Step 0 strip-entry canary and bind its first observation

[gunbai-bot]

Outcome

Freezes the NS-N Step 0 canary around one question: can the corpus-wide import strip be entered, and if not, what is the first typed stop?

The first observation is honestly ObservationUnavailable. It is revision-bound to commit cfb448de521965163e9a82e0a9eb77b311b49f9d, tree 140fbae21fbc209319bbe1a9d9bfbdfd2c5d5dc6, and the exact target/release/gunbc executable built from that revision (SHA-256 4a14d9095b820ad92b7b12752c6464cc0b25f91897c85958feb8bac9ad5c9f3e).

Completed prefix:

1. canary contract frozen
2. source tree pinned
3. compiler executable pinned
4. input/subject manifest pinned

First stop: ApplyTypedImportStrip / TypedSourceRewriteAndStripObservationProducerUnavailable.

The receipt keeps Step0SubjectNotEntered separate from Step0ObservationIncomplete. It does not install #10072's one-off census counts as authority.

Frozen contract

A PR claiming NS-N prerequisite credit may not edit the canary, classifier, subject-entry definition, or controls in the same change. A correction is a separate change and resets the baseline. Later prerequisite claims must show paired movement on this exact canary or remain valuable maintenance that cannot delay Step 0.

Exact command:

target/release/claim_batch --source-root dag --source-root src/v2 --entry dag/test/claim/namespace_step0_canary_witness_test.dag --functions current_main_step0_canary_receipt_is_admitted

Controls

The witness also refuses:

• a receipt relabelled onto a foreign source tree;
• an unavailable/empty observation from a foreign canary contract.

Verification

• pinned gunbc release build completed remotely and produced the recorded executable digest;
• first remote claim run reached resolution and exposed a one-variant transition declaration defect; fixed by making the transition vocabulary closed over both strip and containment-compile transitions;
• follow-up local invocation used an older host compiler and was non-evidentiary;
• required CI is the current-compiler execution.

[gunbai-bot]

Addressed review 58793 across the two subsequent commits.

The admission is no longer a Boolean self-comparison: it returns NamespaceStep0ReceiptRefused { field, cause }, and independently-authored controls now discriminate stale commit, foreign tree, foreign manifest, inconsistent subject entry, empty planted observation, and foreign-tree planted observation at their exact fields. The pinned positive row is deliberately a versioned historical receipt, not a live-tree oracle or a claim that Step 0 executed; its ObservationIncomplete / SubjectNotEntered outcome records the capability audit requested by the stopping ruling.

The receipt is now sole_constructor. The immediate-successor constructor is caller-sealed to test.claim.namespace_step0_canary_witness frontier_receipt; production cannot mint SubjectEntered by writing a receipt. The annotation states that the fixture proves a longer frontier is inhabitable and that the eventual strip producer must own a separate constructor whose inputs are the executed rewrite and observation. Thus the successor remains authorable at the fixture boundary without becoming the section-5 escape hatch.

— sent from gentle-ibex-25