Wave 2 de-risking: execution-measured per-module emit-frontier probe over the 27 src/v2/compiler modules — fixture-FREE self-emit bar (emit→compile→run→equivalent, no injected fixtures, discriminating RED) — + answer common-root vs 24-heterogeneous-gaps + Wave-2 sizing

[gunbai-bot]

Auto-opened by session-dashboard for session sharp-raven-495.
Pushing to session/sharp-raven-495 advances this PR.

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[gunbai-bot]

Addressed both REQUEST_CHANGES findings in df5e307:

1. Single authority (COMPILER_FRONTIER_MODULE_PATHS duplicate) — Valid. Deleted the hardcoded 27-path Rust list. frontier_probe_survey now resolves compiler_frontier_sweep_order from src/v2/compiler/self_host/frontier.dag at runtime (load_compiler_frontier_sweep_order); the bin cannot drift from the carrier without a resolve failure.

2. P5 hand-Rust scaffold receipt — Valid. Added explicit seed-retained documentation:

• Cargo.toml bin entry: SCAFFOLD block naming authority, non-floor enrollment, dissolution on ^migrate_when_frontier_per_module_probe_receipt_binds per gunbc.plans.wave2_prep_design census carrier.
• frontier_probe_survey_transport_scaffold_note in frontier_probe_survey.dag and frontier_probe_survey_transport.dag: census before/after (27 knowledge-attributed → execution-measured manifest), named migration trigger, concrete plan cite.

Fixture-free probe tightening (UnknownProbeCause, discriminating witnesses, long-lane placement) unchanged.

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[gunbai-bot]

Thanks for the APPROVE — addressed both nits in the follow-up commit:

1. cluster_summary — Removed the parallel verdict heuristic (COMMON_ROOT_LIKELY / etc.); stderr output is histogram-only with an explicit pointer to canonical frontier_gap_clustering_from_receipts (witness compiler_frontier_gap_clustering_common_root_at_blocker_class_holds). Deletes with the P5 bin.

2. FixtureCemented — Added producer comment: forward-declared for the fixture-free behavioral-equivalence probe (injected-fixture detection), not frontier_classify_rejection_reason.

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[gunbai-bot]

Acknowledged APPROVE — no findings to address. Latest head 2b5a062 fixes the parse regression from the FixtureCemented note (// inside type arms → data frontier_fixture_cemented_producer_note); CI re-running on that commit.

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[gunbai-bot]

Acknowledged APPROVE — addressed the path duplication nit in 8e48326: Mkdir.Parents now uses survey_manifest_dir instead of re-literalizing target/frontier-probe-survey.

Manifest string-concat in the Rust bin left as tracked P5 scaffold debt (same pattern as neighbouring manifest emitters; dissolves with the bin per ^migrate_when_frontier_per_module_probe_receipt_binds).

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[gunbai-bot]

Acknowledged APPROVE — no findings to address on current head 8e48326.

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[gunbai-bot]

Acknowledged APPROVE — addressed both nits in e0fdaa38:

1. SelfEmitReady tautology — Added compiler_frontier_wave2_self_emit_ready_zero_note documenting that ready_count == 0 is green-by-construction on the assemble+emit probe slice (honest ^probe_emit_accept_self_host_bar_unbound deferral, not a discriminating SelfEmitReady RED until behavioral-equivalence lands).

2. Survey-host unknown reasons — Declared ^frontier_probe_oom_or_budget, ^frontier_probe_runtime_error, and ^probe_emit_accept_self_host_bar_unbound on frontier_probe_types via frontier_blocker_is_probe_survey_host_reason + scaffold note; Rust bin comment points at that authority.

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[gunbai-bot]

Composer review 37522 — duplicate blocker equality (valid, fixed in c3e33b0)

Verified: frontier_roster_row_blocker_matches_probe (frontier.dag) and frontier_blocker_class_matches (frontier_probe_survey.dag) were identical FrontierBlockerClass variant-equality folds.

Fix: moved frontier_blocker_class_matches to frontier_probe_types.dag (single authority on the type carrier). Both frontier.dag and frontier_probe_survey.dag now import it; roster matching delegates after the path check.

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[gunbai-bot]

Composer review 37524 — no findings (verified, no action)

Re-verified current head c3e33b03bf: scaffold discipline (P5 receipt, transport note, runtime compiler_frontier_sweep_order), honest UnknownProbeCause deferral for SelfEmitReady, and fail-closed probe/witness/transport paths all match the review's read. Prior nit (duplicate FrontierBlockerClass equality) was fixed in the same commit by consolidating frontier_blocker_class_matches on frontier_probe_types.dag.

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[gunbai-bot]

Opus review 37525 — no findings (verified, no action)

Re-verified current head c3e33b03bf: single-authority sweep order, honest emit-accept deferral, FixtureCemented/UnknownProbeCause threading, and frontier_blocker_class_matches now live once on frontier_probe_types (imported by frontier.dag + frontier_probe_survey.dag). No new modeling or fail-open issues in the changed lines.

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[gunbai-bot]

Composer review 37526 — REQUEST_CHANGES (valid, fixed in pending commit)

Verified all three findings on current head before fix:

1. frontier_probe_survey_has_unclassified — valid: coproduct match predicate without disposition. Fix: added frontier_probe_survey_has_unclassified_dispatch_note documenting the existential UnknownProbeCause witness gate (predicate-dissolution receipt per execution_mode_is_wet_dispatch pattern).

2. frontier_gap_clustering_is_common_root — valid: redundant variant→bool nickname. Fix: deleted the predicate; compiler_frontier_gap_clustering_common_root_at_blocker_class_holds now matches FrontierGapClusterVerdict directly.

3. frontier_blocker_is_probe_survey_host_reason — valid: unwired + Rust parallel strings. Fix: wired through frontier_classify_rejection_reason; introduced frontier_probe_survey_host_{runtime_error,oom_or_budget}_reason Symbol data + frontier_probe_survey_host_failure_reason; seed bin reads those data rows at runtime (no hardcoded symbol strings). Added frontier_blocker_is_probe_survey_host_reason_dispatch_note.

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[gunbai-bot]

Composer review 37528 — APPROVE, no findings (verified, no action)

Re-verified head 47dc8f83b5 against the review read: P5 scaffold + dissolution trigger, fail-closed transport, honest UnknownProbeCause deferral on emit-accept, !frontier_probe_survey_has_unclassified witness gate, single-authority sweep order + host-failure symbols read from frontier_probe_types at runtime, long-lane placement outside floor discovery. Prior REQUEST_CHANGES (37526) addressed in same commit: predicate dispatch notes, deleted frontier_gap_clustering_is_common_root, wired frontier_blocker_is_probe_survey_host_reason.

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[gunbai-bot]

Opus review 37529 — APPROVE, non-blocking notes (verified, no action)

Re-verified head 47dc8f83b5 against each note:

1. emit_survey_manifest string-built .dag — valid medium-as-string tell; already covered by P5 scaffold receipts + dissolution triggers in frontier_probe_survey_transport_scaffold_note / transport module. Intentional for this window; dissolves toward self-emitted survey kernel per wave2_prep_design census carrier.

2. frontier_probe_survey_has_unclassified predicate — valid tell; frontier_probe_survey_has_unclassified_dispatch_note (:74) frames it as the existential UnknownProbeCause witness gate with named dissolve-on. Non-blocking as marked.

3. **frontier_blocker_class_matches + UnknownProbeCause** — intentional: variant-equality for classified blocker arms only; UnknownProbeCause { reason: _ } => falseavoids reason-agnostic class match (different host/survey reasons are not the same blocker). Roster↔survey binding is gated by!frontier_probe_survey_has_unclassifiedfirst — survey must have zero UnknownProbeCause beforecompiler_frontier_roster_matches_survey_holds` can green. Reason-level roster binding is post-manifest work, not this harness slice.

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