Gate spec-id references on the premise that the repo defines a corpus

[joshft]

Fixes the external review's headline finding: the self-sweep remainder was 0/7 useful — every row an example id in this tool's own doc comments.

The reviewer's proposed fix (stricter annotation grammar / explicit invariant marker) was measured and refuted before implementing: across two real corpora (2,880 and 642 spec-id sightings in shipped code), the dominant real-assertion convention is a mid-comment parenthetical id — the exact textual shape of an explanatory example. A grammar strict enough to kill the examples kills ~80% of the real harvest.

The separator is the referent, not the shape. When the repo defines no spec-id corpus anywhere, a probe-less reference has no possible referent — it is a mention, not a claim. AnchorClaims now suppresses those, and the count is disclosed in the receipt's coverage (schema 0.0.5, suppressed_mentions), because silently dropping remainder rows would be the exact dishonesty the remainder exists to prevent.

Measured on all three legs before this PR:

• Self-sweep: remainder 7 → 0, all 75 verified claims untouched, disclosure line present.
• Both corpus-bearing dogfood repos: receipts byte-identical old-vs-new (modulo probe timings) — the gate is inert where a corpus exists, so true orphans still surface.

What the receipt cannot check here: the measurement numbers above come from repos outside this one; the receipt covers the code and its tests, not the external measurement.

🤖 Generated with Claude Code

https://claude.ai/code/session_015GeUG1gboWiZSnFyzQghyp

[github-actions]

correctful receipt

17 claims — ✅ 17 verified · ❌ 0 refuted · ⚠️ 0 unverified

Change: origin/master...HEAD (404a1be..7a29ffc) — 8 files

⚠️ Unverified remainder (0) — what nothing checked

Empty — every harvested claim reached a probe.

✅ Verified (17)

Tier	Claim	Statement
T1-assertion	TestBuildDefIndexShapes	Build Def Index Shapes
T1-assertion	TestAnchorClaims	Anchor Claims
T1-assertion	TestAnchorClaimsNoCorpus	Anchor Claims No Corpus
T1-assertion	TestAnchorSubVariantFallsBackToParent	Anchor Sub Variant Falls Back To Parent
T1-assertion	TestAnchorChangeScopedDisambiguation	Anchor Change Scoped Disambiguation
T1-assertion	INV-001	Remainder Contains Every Unverified Claim
T1-assertion	INV-002	Refuted Claim Never Enters Remainder
T1-assertion	TestVerifiedClaimCarriesProbeTier	Verified Claim Carries Probe Tier
T1-assertion	INV-007	Refutation Dominates Verification
T1-assertion	TestT0PassConfersNoVerification	T0 Pass Confers No Verification
T1-assertion	TestSuppressedMentionsAreDisclosed	Suppressed Mentions Are Disclosed
T1-assertion	TestRemainderSectionAlwaysRenders	Remainder Section Always Renders
T1-assertion	TestCoverageDisclosesUnreadFiles	Coverage Discloses Unread Files
T1-assertion	TestAnchoringSummaryAndMarkers	Anchoring Summary And Markers
T1-assertion	TestLLMProposedMarker	LLMProposed Marker
T1-assertion	TestRefutedDetailComesFromFailingProbe	Refuted Detail Comes From Failing Probe
T1-assertion	TestReceiptSanitizesPathsAndPinsSHAs	Receipt Sanitizes Paths And Pins SHAs

Harvest coverage: 8 files — 4 claimed · 4 scanned · 0 unread
_{5 spec-id mention(s) not minted as claims — the repo defines no spec-id corpus, so a reference has no possible referent}

_{schema 0.0.5 · exit gate: refuted claims block; the remainder informs, never fails}