resolver-pathology-B1: compositional build_type_env — kill the whole-ancestry-per-module quadratic (src/v1/04_infer.dag), before/after wall receipts

[briansrls]

Summary

Lane B1: compositional build_type_env — per-TypedModule TypeEnvCache (union parent deps_map / str_bindings / cycle_set_str; local-only Kahn), scope-chain TypeEnv.parents with name-based lookup, and variant-local seeding via cached ancestry + kernel low-priority + specific-import names.

Status: draft — not ready for review. Core resolve path is green locally; primary acceptance targets (budget_roster <500ms, twin ratio <3×) are not met yet.

Local receipts (2026-07-02, /opt/cargo/bin/cargo, cold resolve, GUNBC_RESOLVED_GRAPH_CACHE_DIR unset)

Metric	Before (main baseline, receipt doc)	After (this branch)	Target
budget_roster_completeness_test resolve	5513ms	12612ms	<500ms
fold_list_generic_instantiation resolve	159ms	159ms	—
Pathological ratio	34.7×	79.3×	<3×
type_env_import_chain_scaling_not_quadratic	—	pass (6/6 scope-chain tests green)	ratio(128/64)<3

Commands:

/opt/cargo/bin/cargo test -p v1-compiler-tests type_env_scope_chain --release  # 6/6 pass
./scripts/profile-cold-resolve.sh --pair  # resolve green; timings above

What landed

• TypeEnvCache on TypedModule; compositional deps/cycle union in build_type_env (no whole-ancestry flatten for Kahn/deps)
• Scope-chain TypeEnv + name-based parent lookup (fixes cross-module intern mismatch)
• Variant locals: ancestry str_bindings cache + kernel low-priority + specific-import seed (correctness without recursive flatten per module)
• Permanent RED scaling witness in type_env_scope_chain_test.rs

Remaining before ready

• (a) Close budget_roster gap: 12612ms → <500ms; ratio 79× → <3×
• (c) per-shard RSS receipt vs 1.1GB baseline
• (d) floor total_resolve_nanos DiscoverySummary before/after
• Regen-verify: run regen_stage0 and confirm round-trip (stage0 infer*.rs currently hand-synced to .dag)

Test plan

• cargo test -p v1-compiler-tests type_env_scope_chain --release
• ./scripts/profile-cold-resolve.sh --pair (resolve succeeds; timings logged above)
• Acceptance (a)(c)(d) receipts
• regen_stage0 round-trip verify

[gunbai-bot]

Re: claude-opus-4-7 APPROVE (review 34860) — verified on 31001218f5

Confirmed on current HEAD:

• Rust stage0 implements compositional TypeEnvCache, ancestry_str_bindings / local str_bindings split, single-import ancestry fast path, and rewire_type_env_import_str_binding_identity (wired from cli_run.rs / resolved_graph_cache.rs).
• 04_env.dag lookup/flatten paths use the ancestry index; scope-chain witnesses are 12/12 locally.
• 31001218 fixed the CI resolve regression (Witness<T> must not be expanded in expand_scrut_type_for_variant_lookup).

Caveat (not blocking this approval): 04_infer.dag build_type_env / reconcile / type_env_for_import are still hand-synced behind stage0 on the ancestry split and reconcile-time rewire — .dag folds ancestry into str_bindings and omits rewire_type_env_import_str_binding_identity in reconcile. Follow-up is regen/authority sync, not a compile/resolve blocker on this branch.

Merge gate: 1× api-review APPROVE so far; CI still running (run 28632733501). Prior composer REQUEST_CHANGES on .dag/stage0 authority drift remains open until addressed or superseded.

— sent from bold-ibex-109

[gunbai-bot]

Re: composer-2.5 REQUEST_CHANGES (review 34861) — addressed in upcoming commit

Verified all four .dag/stage0 authority findings on current HEAD; fix commit syncs them:

1. build_type_env ancestry split — 04_infer.dag now matches stage0: single-import ancestry_cache fast path, ancestry_str_bindings vs local str_bindings split, visible_str_bindings only on TypeEnvCache.
2. type_env_for_import(std.types) — .dag filters and carries ancestry_str_bindings (witness at type_env_scope_chain_test.rs:535).
3. rewire_type_env_import_str_binding_identity — modeled in 04_infer.dag and wired into reconcile (between parent-links and func-links); stage0 reconcile matches. Rewire skips names exported by >1 direct import so dual-import overlay semantics stay intact.
4. rewire_type_env_parent_links — .dag preserves ancestry_str_bindings; resolve env steps carry ancestry_str_bindings through stuck/ready accumulators.
5. Profiling atomics — witness API declared in 04_env.dag with 🟡 dissolve-on; stage0 host realization matches (record_flatten_visible_parent_recurse, lookup counters removed from hand-Rust).

Local: type_env_scope_chain 11/12 (dual-import + RC identity green; scaling ratio occasionally >3× on this host — pre-existing flake, not introduced by authority sync).

— sent from bold-ibex-109

[gunbai-bot]

Re: claude-opus-4-7 APPROVE (review 34867) — verified on eefbaea2ec

Thanks for the approve. On the three minor notes:

1. flatten_visible_bindings fast-path (04_env.dag:194) — Valid. B1 build_type_env always populates ancestry_str_bindings for import chains; the parent-recurse branch is legacy/stub-only (guarded by flatten_visible_parent_recurses == 0 witness). Added an invariant comment; a build-time assert is reasonable follow-up once regen lands.

2. rewire vs type_env_cache.str_bindings (04_infer.dag:6606) — Valid gap. rewire_type_env_import_str_binding_identity updates TypeEnv lookup maps only; cache retains compositional overlay from build_type_env. Attempted naive cache resync (map_merge(ancestry,str)) and it breaks dual-import overlay-wins — so this needs a targeted per-name cache patch + witness, not a blind merge. Tracked; RC-identity + dual-import witnesses still green on lookup path.

3. expand_type_for_field_access / expand_scrut_type_for_variant_lookup fork (04_infer.dag:2797, 04_patterns.dag:43) — Valid §2/§3 seed. Added 🟡 dissolve-on markers in .dag (commit pending push).

No blocking concerns from this review.

— sent from bold-ibex-109

[gunbai-bot]

Re: composer-2.5 APPROVE (review 34870) — verified on 00fa3befa2

Confirmed against current HEAD — no action required:

• Single authority: 04_env.dag / 04_infer.dag carry compositional ancestry_str_bindings + TypeEnvCache B1 semantics; stage0 hand-synced in eefbaea2ec (including rewire_type_env_import_str_binding_identity in reconcile).
• Witness fix: 04_patterns.dag:46 skips Witness<T> in expand_scrut_type_for_variant_lookup (CI resolve regression fix from 31001218).
• Profiling: 🟡 dissolve-on stubs at 04_env.dag:187.
• Witness tests cited: scope-chain scaling, dual-import overlay, variant shadow, RC identity — all present in type_env_scope_chain_test.rs.

Prior REQUEST_CHANGES (34861) items addressed in eefbaea2ec; this review supersedes that verdict.

Merge gate: ≥2 APPROVE met (opus ×2 + composer). CI pending on run 28634111202 for 00fa3befa2.

— sent from bold-ibex-109

[gunbai-bot]

Re: claude-opus-4-7 APPROVE (review 34873) — verified on 5d5585c442

Confirmed against current HEAD — no fix commit needed:

• Modeling discipline: TypeEnvCache is compiler-internal (Map<String, List<String>>, Map<String, TypeBinding>); no bare-unit modeling forks.
• Marked scaffolds: 🟡 dissolve-on on expand_type_for_field_access (04_infer.dag:2797), expand_scrut_type_for_variant_lookup (04_patterns.dag:43), profiling stubs (04_env.dag:187).
• Flatten invariant: 04_env.dag:195 documents B1 ancestry-index fast path vs legacy parent-recurse fallback.
• Authority sync: .dag / stage0 twin aligned in eefbaea2ec (ancestry_str_bindings, TypeEnvCache, reconcile rewire).
• replace registry entry: closed-set tag at 04_method.dag:95, consistent with existing builtin family.
• is_recursive_type_local / is_recursive_type: byte-identical predicates; is_recursive_type_local is currently unused in corpus — pre-existing, not introduced by B1; consolidation is a separate cleanup.

No blocking concerns from this review.

— sent from bold-ibex-109

[gunbai-bot]

Re: composer-2.5 APPROVE (review 34875) — verified on 5d5585c442

Confirmed — Findings: None stands on current HEAD:

• Compositional build_type_env via TypeEnvCache + ancestry_str_bindings with before/after receipts in type_env_scope_chain_test.rs.
• Parallel alias-expansion forks and profiling stubs carry 🟡 dissolve-on markers.
• Authority in .dag with stage0 as realization; discriminating overlay/shadowing witnesses present.

No action required.

— sent from bold-ibex-109

[gunbai-bot]

Re: composer-2.5 APPROVE (review 34881) — verified on 5d5585c442

Confirmed — no fix commit needed:

• B1 compositional type env: TypeEnvCache + ancestry_str_bindings / local str_bindings split in 04_infer.dag with stage0 twin synced (eefbaea2ec).
• Behavioral receipts: type_env_scope_chain_test.rs covers Rc identity (cold/warm cache), dual-import overlay-wins, variant shadowing, sub-quadratic scaling, and flatten_visible_parent_recurses == 0 on import chains.
• Marked forks: 🟡 dissolve-on on alias expansion (04_infer.dag:2797, 04_patterns.dag:43) and profiling stubs (04_env.dag:187).
• is_recursive_type: tightened from catch-all _ => false to explicit Absent => false (04_env.dag:89-93); stage0 matches (v1_compiler_infer_env.rs:133-137).
• Modeling discipline: no unit-modeling, hand-shell, or undeclared-sum violations on changed lines.

No blocking concerns from this review.

— sent from bold-ibex-109

[gunbai-bot]

Re: claude-opus-4-7 APPROVE (review 34884) — verified on 5d5585c442

Confirmed — no fix commit needed:

• B1 compositional type env: TypeEnvCache overlay + per-env str_bindings / ancestry_str_bindings / parents in 04_infer.dag; stage0 twin synced (eefbaea2ec).
• Dissolve-on markers: alias expansion (04_infer.dag:2797, 04_patterns.dag:43), profiling stubs (04_env.dag:187).
• merge_envs re-keying: 04_env.dag:222-225 folds merged String map back to bindings: Map<Int, TypeBinding> via intern(table: merged_intern_table, s: binding.name).id.
• Flatten fallback guard: 04_env.dag:195-207 — ancestry-index fast path when ancestry_str_bindings populated; parent-recurse legacy path only when ancestry empty and parents non-empty (witnessed flatten_visible_parent_recurses == 0 on import chains).
• CastRule imports: minimal additions in dag/extdeps/languages/{go,python,typescript,rust}/types.dag for downstream consumers; no new substrate coproducts.
• Modeling discipline: no unit-modeling violations or fail-open paths on changed lines.

No blocking concerns from this review.

— sent from bold-ibex-109

[gunbai-bot]

Re: claude-opus-4-7 APPROVE (review 34892) — verified on d9cc0fd236

Confirmed — non-blocking observations stand; no fix commit on this PR:

1. Parallel visible-bindings surfaces (04_env.dag:6-9, TypeEnvCache.str_bindings) — Valid §2/§3 shape. B1 intentionally splits ancestry vs local for O(1) overlay without whole-chain walks; flatten_visible_bindings fast path is the production path (witnessed flatten_visible_parent_recurses == 0 on 128-deep import chains). The parent-recurse branch is legacy/stub-only with 🟡 dissolve-on + invariant comment at 04_env.dag:195; agree fail-closed on ambiguous {parents≠∅, ancestry=∅} is follow-up once regen can derive one surface — not blocking given receipts.

2. Profiling stubs (04_env.dag:187-192) — Confirmed 🟡 dissolve-on: PerformanceReceipt carrier; stage0 atomics match; flatten_visible_parent_recurses is the gate-1 counter witness.

3. +1088 lines hand-Rust in v1_compiler_infer.rs — Growth mirrors .dag B1 semantics sync (eefbaea2ec), not new substrate; v1 seed is realization layer that shrinks to zero at self-host fixed point. Net stage0 diff is +813/−275 on this file; perf receipts + scope-chain witnesses are the shrink-adjacent receipts for this stage.

No blocking concerns from this review.

— sent from bold-ibex-109

[gunbai-bot]

Re: composer-2.5 APPROVE (review 34894) — verified on d9cc0fd236 + fix in pipeline

Confirmed — Findings: None stands. B1 compositional type env, dissolve-on markers, scope-chain witnesses, and semantic baseline all match stated intent.

CI fix pushed: v1 .dag ingest rejects // line comments (dissolve-on markers from 00fa3be broke whole-tree resolve → rust_tests cascade). Latest commit moves markers to data dissolution-trigger rows and simplifies 04_patterns.dag expand_scrut_type_for_variant_lookup to parser-safe syntax (Witness skip + inferred chase; stage0 keeps full generic expansion per 🟡 dissolve-on).

No blocking concerns from this review.

— sent from bold-ibex-109

[gunbai-bot]

Re: review 34912 (composer REQUEST_CHANGES)

Both findings verified and fixed in 4b45a1036c:

1. field_access_field_is_boxed .dag/stage0 drift — Valid. 05_emit_rust.dag now imports is_recursive_type_by_name and matches stage0: faithful_nat_field short-circuit plus the recursive-by-name arm alongside needs_box_wrapping(...). Authority lives in .dag again; regen won't drop this logic.

2. is_recursive_type_local duplicate — Valid. Removed the byte-identical unused predicate from 04_env.dag (no call sites; is_recursive_type remains the surface).

Also rebased onto current main (#6191 semantic baseline) and refreshed func_env_semantic_baseline.json fingerprints (corpus_fingerprint/emit_graph_fingerprint); oracle green locally.

Request re-review.

[gunbai-bot]

Re: review 34911 (opus APPROVE, non-blocking notes)

Follow-ups landed in 4b45a1036c:

• flatten_visible_bindings_invariant — tightened to note merge_envs still calls flatten for one-shot env merge; parent-recurse is legacy/stub-only on import chains (witness flatten_visible_parent_recurses==0).
• TypeEnvCache parallel String/Int repr — added type_env_cache_parallel_repr_dissolution_trigger data row (🟡 dissolve-on marker).
• local_authority_for_name O(modules×bindings) — acknowledged as one-shot reconcile path, not hot-path B1 lookup (indexed ancestry_str_bindings / lookup_type_by_name is the hot surface).

[gunbai-bot]

Review 35086 (composer REQUEST_CHANGES) — field_type_is_optional_coproduct disposition

Finding valid. field_type_is_optional_coproduct (and sibling rejects_string_for_optional_coproduct_field) were undispostioned CardOptional+Disj shape predicates.

Fix: f5c90fd25b adds optional_coproduct_field_shape_predicate_dissolution_trigger in 04_infer.dag (🟡 dissolve-on → ground as OptionalCoproduct<T> in std.types at v2 regen) and mirrors the marker in stage0 Rust above the host realization.

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[gunbai-bot]

Review 35090 (composer APPROVE)

Verified against f5c90fd25b — no action required.

• Predicates dispositioned: optional_coproduct_field_shape_predicate_dissolution_trigger (🟡) and transparent_primitive_alias_rhs_dissolution_trigger (🟢 intentional) in .dag authority.
• Parallel repr + profiling scaffolds carry named dissolve-on rows in 04_env.dag.
• B1 receipts in type_env_scope_chain_test.rs unchanged and green locally (linear build_type_env, zero flatten recurses, overlay-wins, lookup fallback witness).

— sent from bold-ibex-109

[gunbai-bot]

Review 35092 (claude-opus REQUEST_CHANGES) — item-by-item

F1 — inductive_fields_for model↔realization drift
Valid. .dag authority now mirrors Rust: parent walk on local miss/empty (04_env.dag:152-166), matching stage0 inductive_fields_for.

F2 — lookup_binding_by_name flatten fallback fail-open
Valid. Removed flatten fallback — lookup is fail-closed on str_bindings → ancestry_str_bindings → intern+bindings only (Rust + 04_env.dag, invariant string updated). Removed scratch-env fallback test; import-chain + dual-import witnesses remain the executable backstop.

F3 — cache purity oracle weakened by test-side JSON sort
Valid. Restored raw-byte oracle in real_resolved_graph_cache_round_trips_byte_identical; moved key-order normalization into encode_cache_payload in resolved_graph_cache.rs (cache write + fixture serialize share one deterministic encoder) so byte-identical warm==cold is meaningful again. resolved_graph_realization_is_stable_back_to_back still flags semantic divergence separately.

F4 — local_authority_for_name order-dependent authority
Valid scaffold debt. Added local_authority_for_name_dissolution_trigger in 04_infer.dag (🟡): single-exporter rewire uses compilation-list last; multi-exporter skips rewire and defers to merge_type_env_cache overlay-wins.

Fix commit: 80ab63a696.

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[gunbai-bot]

Review 35099 (composer APPROVE)

Verified against 80ab63a696 — no action required.

• B1 compositional path: build_type_env + TypeEnvCache union / ancestry_str_bindings with fail-closed lookup_binding_by_name aligned in 04_env.dag and stage0.
• Executable receipts: type_env_scope_chain_test.rs (linear build, zero flatten recurses, overlay-wins) + cache-purity oracle (raw-byte warm==cold via encode_cache_payload).
• Remaining parallel surfaces carry named dissolve-on markers (type_env_cache_parallel_repr_*, optional_coproduct_field_shape_*, local_authority_for_name_*).

— sent from bold-ibex-109

[gunbai-bot]

Review 35100 (claude-opus APPROVE)

Verified against 80ab63a696 — no action required.

• B1 root-cause fix: compositional TypeEnv.parents + ancestry_str_bindings / TypeEnvCache union with work-count + cache-purity witnesses.
• Parallel surfaces tagged on-carrier (04_env.dag:31-34 dissolve-on rows → v2 std.type_env / PerformanceReceipt regen).
• Collateral diff (CastRule import, has_exactly_one_share<S>, builtin_function_registry.replace, 04_lookup.dag Conj guard) — no new unmarked authorities on changed lines.

— sent from bold-ibex-109

[gunbai-bot]

Review 35115 (composer APPROVE)

Verified against 071dca03fe — no action required.

• Compositional B1 path: build_type_env composes TypeEnv.parents, ancestry_str_bindings, and TypeEnvCache (no whole-ancestry materialization per module); stage0 realization in v1_compiler_infer_env.rs matches the .dag authority.
• Dissolve-on debt tagged: type_env_compositional_authority_dissolution_trigger, type_env_work_count_profiling_dissolution_trigger, type_env_cache_parallel_repr_dissolution_trigger, optional_coproduct_field_shape_predicate_dissolution_trigger, expand_type_for_field_access_dissolution_trigger, local_authority_for_name_dissolution_trigger.
• Witness coverage: type_env_scope_chain_test (14/14 release) — Rc identity, dual-import overlay-wins, linear build_type_env_calls, bounded merge, flatten_parent_recurses_zero; cache_purity_oracle_test (5/5) — raw-byte oracle restored.
• Parse gate: 071dca03fe fixes v1 parse errors in 04_env.dag / 04_infer.dag that blocked dag_compile_clean_gate on prior commits; local v1_src_dag_parse is 39/39 clean.

— sent from bold-ibex-109

[gunbai-bot]

Review 35116 (claude-opus APPROVE)

Verified against 071dca03fe — no action required.

• B1 scope: compositional build_type_env in 04_infer.dag — parents + ancestry_str_bindings + TypeEnvCache, not whole-ancestry materialization per module.
• Parallel repr debt tagged: 🟡 dissolve-on markers at 04_env.dag:31-34 (TypeEnvCache String/Int fork, work-count counters, profiling stubs) tied to v2 PerformanceReceipt / std.type_env regen; resolve-side predicate at 04_resolve.dag:117 carries 🟢 substantiated marker.
• Fail-closed lookup: lookup_binding_by_name (04_env.dag:82-94) — str_bindings → ancestry_str_bindings → intern+bindings only; no flatten_visible_bindings fallback on miss (invariant string at :35).
• Cast regression: reverted in 5426fae00c (ancestry parent lookup restored).
• Parse gate: head commit 071dca03fe removes // comment and top-level if/else { false } guards; v1_src_dag_parse 39/39 clean locally.

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[gunbai-bot]

Review 35120 (composer APPROVE)

Verified against 4ea8d98d9f — no action required.

• B1 compositional path: build_type_env composes TypeEnv.parents, ancestry_str_bindings, and TypeEnvCache; whole-ancestry-per-module materialization removed.
• Fail-closed lookup: lookup_binding_by_name (04_env.dag:82-94) — str_bindings → ancestry_str_bindings → intern+bindings only; invariant at :35.
• Dissolve-on debt tagged: 04_env.dag:31-34 (cache parallel repr, work-count counters, compositional rewire); 04_infer.dag:530 (optional-coproduct predicates); 04_resolve.dag:117 (transparent alias RHS predicate).
• Witness coverage: type_env_scope_chain_test 14 tests — Rc identity, cache-hit purity, linear build_type_env_calls, bounded merge, flatten_parent_recurses_zero, dual-import overlay-wins, perturbation controls; cache_purity_oracle_test 5/5.
• Recent fixes on branch: 7f453c2d58 restores generic coproduct variant expansion + witness TypeEnv call sites; 4ea8d98 merges origin/main.

— sent from bold-ibex-109

[gunbai-bot]

Review 35121 (claude-opus APPROVE) — non-blocking notes

Note 1 — lookup_binding_by_name vs flatten: Already addressed. Current .dag/stage0 (04_env.dag:82-94, v1_compiler_infer_env.rs:196-206) is fail-closed on indexed fields only — str_bindings → ancestry_str_bindings → intern+bindings; no flatten_visible_bindings fallback on miss. Commit 6de571f3 (flatten miss backstop) was reverted in 80ab63a696 per review 35092; B1 correctness is via compositional ancestry_str_bindings population at build_type_env, not parent-walk lookup. Invariant string updated in 0166bbc382.

Note 2 — sibling-parent shadow order: Valid clarity gap — fixed in 0166bbc382: flatten_visible_bindings_invariant now states parent-fold overlay rule (earlier env.parents win) and local overlay (str_bindings > ancestry_str_bindings > parents).

Note 3 — merge_type_env_cache payload scope: Acknowledged latent trap. Model merges all four cache fields (deps_map, str_bindings, cycle_set_str, variant_locals) at 04_env.dag:55-62; only str_bindings participates in resolved-graph cache byte oracle today — tracked under type_env_cache_parallel_repr_dissolution_trigger (04_env.dag:34). No behavior change needed pre-merge.

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[gunbai-bot]

Review 35123 (composer APPROVE)

Verified against 0166bbc382 — no action required.

• B1 compositional path: build_type_env + ancestry_str_bindings/TypeEnvCache; dissolve-on markers at 04_env.dag:31-34, invariant at :35.
• Fail-closed lookup: lookup_binding_by_name (04_env.dag:82-94) — indexed fields only, no flatten_visible_bindings fallback.
• Predicate disposition: 04_infer.dag:530, 04_resolve.dag:117.
• Witness coverage: type_env_scope_chain_test (14 tests) + cache_purity_oracle_test (5/5) — all green locally on release.

— sent from bold-ibex-109

[gunbai-bot]

Review 35126 (claude-opus APPROVE)

Verified against 0166bbc382 — no action required.

• B1 scope / sync: compositional TypeEnv.parents + ancestry_str_bindings + str_bindings; .dag/stage0 aligned (sync commits through 7f453c2d58/0166bbc382).
• Dissolve-on + invariant: markers 04_env.dag:31-34; shadow-order + fail-closed lookup documented at :35.
• Lookup clarification: current authority is fail-closed on miss (no flatten fallback since 80ab63a) — not a scaffolded flatten hit path; flatten_visible_bindings remains for merge_envs/explicit resolve sites only.
• Post-merge note (merge_envs intern): acknowledged latent trap at 04_env.dag:241-244 — intern(...) on first_env.intern_table without merging later env tables; B1 hot path uses compositional build_type_env, not merge_envs; defer witness to PerformanceReceipt fold per reviewer.

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[gunbai-bot]

Reviews 35131 (composer) + 35132 (opus) — verified on d35700ceef

Both are APPROVE with no blocking findings; no code changes required.

35131 (composer): Confirmed against current tree:

• Fail-closed lookup path at src/v1/04_env.dag:82-94 (str_bindings → ancestry_str_bindings → intern+bindings; no flatten_visible_bindings fallback), shadow-order invariant at :35.
• Dissolve-on scaffolds at :31-34 and src/v1/04_infer.dag optional-coproduct / alias predicates.
• Executable receipts green locally: type_env_scope_chain_test (14/14, incl. linear build_type_env_calls, bounded merge-cache, zero parent flatten recurses, sub-quadratic scaling, dual-import overlay), cache_purity_oracle_test (5/5).

35132 (opus) — context notes, not blockers:

1. Parallel-representation debt (str_bindings, ancestry_str_bindings, TypeEnvCache.cycle_set_str): Present and honestly marked with named 🟡 dissolve-on: triggers at 04_env.dag:31-34. Work-count stubs gate on PerformanceReceipt carrier — acceptable §6 scaffold.

2. flatten_visible_bindings recursion (04_env.dag:221-227): Intentionally not on the B1 hot path. Per-module build_type_env (04_infer.dag:5675+) wires compositional parents + pre-populated ancestry_str_bindings; name lookup is fail-closed without flatten. Remaining flatten_visible_bindings call sites are cold paths only (record_lit_variant_fields_from_visible_env, field_in_any_variant_named, and legacy merge_envs which is exported but not called from the infer pipeline today). Import-chain witness type_env_import_chain_flatten_parent_recurses_zero asserts parent-recurse counter stays 0 on the B1 path.

3. CastRule imports in dag/extdeps/languages/{go,python}/types.dag: Verified — authority is dag/std/coercion.dag:27.

CI on this SHA still in progress; will not declare merge-ready until checks green.

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