feat(pre-push-safety-net): export the enumerated operation inventory (M1b 10.4)

A taint answer reports traced flows, so an absent row means either that the
operation is not present or that no traced path reached it. Change comparison
needs that distinction to say a change introduced an operation, and reachability
is deliberately bounded, so the two can never be separated from flow rows alone.
That is why the veto guarding the confusion is permanently true on any real
Express application, and why it could be neither discharged nor safely removed.

The taint query now exports one row per operation it enumerated in scope, plus a
completion marker. The marker is what makes an empty inventory meaningful:
without it a scope that was never enumerated and a scope holding no such
operation are indistinguishable.

Comparison separates three outcomes on a changed line: the operation is present
in the base without a traced flow, which is a reachability statement and not
novelty; the operation is absent from an enumerated base, which establishes that
the change introduced it; or the base scope was never enumerated, which stays
explicitly unresolved. A malformed inventory row is not an empty inventory.

The arbiter now skips any row carrying a kind, so an inventory row cannot be
normalized into a flow with an empty source that names no attacker input.

Verified against the real engine on an authored two-revision JavaScript control:
the operation is enumerated on both sides, the base carries it with zero traced
flows, the zero-operation marker appears for an empty scope, and answers and
findings are unchanged. No new sink inference, alias resolver or second source
IR. 1,354 tests passed, nine skipped. Rollout stays NO-GO.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01EmM1j46qgKMh3zqD1QMwEo

.kiro/specs/pre-push-safety-net/tasks.md

@@ -292,13 +292,14 @@ Preserve all completed task evidence below.
   - _Depends: 10.2_
   - _Requirements: 2.4, 3.4_
   - _Verified 2026-09-16:_ 1,347 tests passed, nine skipped; Ruff/format/mypy passed. Ambiguity is no longer inherited as a context gap by every question, and no longer blocks the transaction comparison; it is decided per operation by the correspondence classifier. Controls prove a uniquely mapped or newly introduced operation stays comparable in a file with repeated unchanged lines, an operation needing an ambiguous anchor stays unresolved, and any other transaction gap still blocks. The mapping is still withheld and still reported in aggregate coverage.
-- [ ] 10.4 Export the enumerated operation inventory so absence is provable
+- [x] 10.4 Export the enumerated operation inventory so absence is provable
   - **Prerequisite discovered 2026-09-16, not in the original plan.** The 10.1-10.3 rerun showed the remaining two vetoes cannot be scoped or relaxed soundly as written. A taint answer reports flows, so an absent row means either that the operation does not exist in the base or that no traced flow reached it. `dynamic_external_or_depth_context_unresolved` exists precisely to stop the second being read as the first, and on a real Express application it is always true, because ordinary framework and dependency calls have unresolved destinations. It therefore carries no discrimination and can never be discharged, while removing it would make an unreached operation look absent.
   - Export the operations the query actually enumerated in the question's scope, separately from the flows it traced, so absence of an operation is established by the inventory rather than by the absence of a flow. Sanitizer and source facts are unchanged; this adds no detector, alias resolver or second IR.
   - Done when a base answer distinguishes "this operation does not exist here" from "no traced flow reached it", with an unenumerated scope remaining explicitly unresolved.
   - _Boundary: contributor-scan query/evidence contract, Delta and Actionability Policy_
   - _Depends: 10.1_
   - _Requirements: 2.1, 2.2, 3.4, 8.1, 8.2_
+  - _Verified 2026-09-16:_ 1,354 tests passed, nine skipped; Ruff/format/mypy passed. The taint query exports one row per enumerated operation plus a completion marker, which is what makes an empty inventory meaningful. Comparison now separates three outcomes: operation present in the base without a traced flow, operation absent from an enumerated base, and a base scope never enumerated, which stays explicitly unresolved along with any malformed inventory. The arbiter skips every row carrying a kind, so an inventory row cannot become a flow with an empty source. Real-engine smoke on an authored two-revision JavaScript control confirmed emission, the zero-operation marker and unchanged answer integrity: `benchmarks/measurements/2026-09-16-operation-inventory-smoke.json`. Pre-inventory fixtures were given an enumerated base, since an unenumerated one can no longer establish absence.
 - [ ] 10.5 Make the external and dynamic context boundary question-owned
   - M1a recorded `dynamic_external_or_depth_context_unresolved` on the target's own question. The flag is computed over every in-scope method, so one unresolved call anywhere vetoes every question.
   - With 10.4 supplying inventory evidence, bind the boundary to what it actually limits: reachability, not enumeration. A question establishing absence from the inventory no longer needs complete reachability; a question asserting a traced flow still does. Unknown ownership remains a blocker; absent evidence of independence is not proof of independence.