Repair the derived stage0 partition: five unrostered modules; retire the extdeps-base tier the chain could not express

[gunbai-bot]

PR body — stage0 derived-partition repair

Title: Repair the derived stage0 partition: five unrostered modules, and the extdeps-base tier the chain could no longer express

What broke

cargo check -p v1-stage0-std-core has been red on main ("6 previous errors") with none of it CI-visible: DagCompileCleanGate is dag-only and the release build is -p v1-compiler (the flat seed crate), which the partition crates are not dependencies of — the same hole class ci_v1_compiler_tests_compile_gate_note documents for v1-compiler-tests. Two distinct defects, one carrier:

1. Membership rot (4 modules, 3 crates). Flat-crate modules gained partitioned consumers without ever being added to a partition roster in src/v2/workflow/rust_crate_partition.dag:

• std_occurrence_identity — re-exported by v1_std_core since Add shared authored-occurrence identity transport #7352 (220b556) → 3 of the 6 std-core errors
• extdeps_units_dimensionless / extdeps_units_iec_80000_13 / extdeps_units_iso8601 — re-exported by std_measure → the other 3
• std_trait_derive_shape — used by extdeps_languages_rust_emit; latent (crate aborts earlier today)
• v1_compiler_infer_occurrence_binding — used by infer_env/infer_sigs; latent likewise

The latent two were found by a full sweep (every crate::X reference from every partitioned member checked against the partitioned universe), not by iterating compile errors, so this closes the absence class in one pass.

2. A chain-order defect the units trio exposes. The crate chain is strictly linear (runtime ← std_core ← std_surface ← extdeps_base ← …), but std_measure (std-core) consumes extdeps.units.*, which need extdeps_uri/extdeps_external_authority — rostered in stage0_extdeps_base, above std-core. A std surface citing the extdeps rows that ground it is the sanctioned direction (DESIGN §3, layer-DAG deletion 2026-07-24); the hand-drawn chain predates it and cannot express it. No pure roster row fixes this: the units modules must sit at-or-below their consumer and at-or-above their deps, and the chain puts those in the wrong order.

The fix

By each module's actual dependency set, extdeps_uri (needs std_types+runtime) and extdeps_external_authority (needs std_decl_ref/std_roster_frontier/std_types/extdeps_uri) are std-core-tier facts — so the whole grounding cluster (extdeps_uri, extdeps_external_authority, the three units modules) moves into the std-core roster, beside their consumer std_measure. That empties the extdeps_base unit, so its crate row is retired rather than shipped hollow: declared targets move 8→7 physical / 7→6 module-bearing in the same authority (the derived-vs-declared witnesses compare both sides honestly), downstream reexport_packages drop the package, and src/v1/stage0_extdeps_base is deleted. Placements for the other two: std_trait_derive_shape → std_surface (std module, core-only deps, consumed from extdeps-languages above); v1_compiler_infer_occurrence_binding → v1-infer beside its consumers (member pin 6→7 updated in the witness). Six edge-census rows added mirroring the existing style (std_measure→units, rust_emit→trait_derive_shape, infer_env/sigs→occurrence_binding).

Then the derived chain — no generated file hand-edited:

1. gunbc run --entry dag/tools/generated_artifact_gate.dag --function main_wet → dag/gunbc/stage0_crate_partition_generated.dag
2. two-generation regen_stage0 (regen → rebuild → regen) → gunbc_stage0_crate_partition_generated.rs, crate roots, workspace members region
3. regen_stage0 --verify clean at the fixed point

Verification

• cargo check -p v1-stage0-std-core — the exact main repro flips green
• cargo check --workspace green (all partition crates, including the two latent instances)
• cargo fmt --all --check clean; regen_stage0 --verify divergence 0
• Witnesses green by execution: rust_crate_partition_witness_test.dag (18 fns) + generated_artifact_drift_test.dag (8 fns)

Deliberately out of scope (operator decisions, not silently taken)

• CI enrollment: a partition-crate compile gate (the ci_v1_compiler_tests_compile_gate_note fmt-amendment pattern applied here, e.g. cargo check --workspace or per-partition-crate checks) would have caught all of this weeks ago; enrolling it is a CI-cost decision that belongs to the operator. This PR repairs and enrolls nothing.
• Topology note for the lane owner: the extdeps-base retirement is the minimal honest closure of the straddle inside the interim HandExplicit partition (which PolicyPartition later re-derives anyway). If a different shape is preferred (e.g. re-tiering the chain), that supersedes this interim edit cheaply — the authority is one file.
• Pre-existing, untouched: src/v1/stage0_core and src/v1/stage0_crates.dag (the earlier split) remain tracked on disk and are not workspace members; noticed during the sweep, left as found.

🤖 Generated with Claude Code

[gunbai-bot]

CI note: the ci job's single failure is 'extdeps_scope_placement_gate_passes returned Bool(false)' - the repo-wide floor red inherited from the #7571 gate x #7573 unenrolled-file merge race, not this change (build/regen/heal all pass; regen confirms the self-host fixed point). The standalone enrollment repair is #7640 (green, 2 approvals, awaiting operator merge). I will integrate main and refresh CI here once it lands. - sent from clever-ferret-451

[gunbai-bot]

CI red on this head is the inherited main red, not this diff: the floor's compile-clean refuses dag/test/claim/rest_exchange_replay_test.dag:44 (bare-string input_digest vs the ContentHash coproduct) — the replay layer of the fleet incident, present on main itself. The canonical repair is the frozen vehicle #7648 (currently at bar: 2/2 exact-head approvals, floor running). No fix will be pushed here — that would duplicate the single vehicle. Once #7648 merges, this branch re-integrates main and CI re-runs; the partition repair itself is verified by execution (regen fixed point divergence 0, workspace green, 26/26 partition witnesses). — sent from clever-ferret-451