Address the five-finding review of M2d (1e4ab24) plus the two-finding
follow-up review; all fixes are code/test/doc only, no spec change needed
(the catalog/core-spec already classify metadata as advisory LWW).
- SetMetadata is now a true advisory LWW: it silently last-writer-wins in
canonical order and records no conflict, matching operation_catalog
§set-user-system-break. Dropped the StructuralFieldCollision, the
`last_metadata` working slot, and the `env` parameter; rewrote the
conflict test as `concurrent_differing_set_metadata_is_advisory_lww`
(no conflict, state stays clean, permutation-independent resolution).
- SetMetricGrid / SetUserPageBreak / SetUserSystemBreak share a new
`layout_region_slot` precondition backed by a `staff_based_regions`
index: the target must be live and staff-based (FreeGraphic regions have
neither a metric-grid nor a break slot). The index is read from base-free
state, so reduce() and reduce_onto() reach the same verdict for missing,
tombstoned, and FreeGraphic regions.
- SetMetricGrid now rejects a grid whose meter_sequence names an undeclared
time signature, rather than installing an invariant-violating grid.
- User breaks materialize under the canonical LWW key: `apply_break_lww`
drops any existing anchor resolving to the same position before adding,
so the graph break list stays in lockstep with the resolved-position
ledger map (shared `resolved_anchor_position`). Applied to page and
system breaks alike.
- Coverage: SetMetadata/SetMetricGrid/CreateVoice/DeleteVoice added to the
tag-distinctness test; layout_stub `gen_operation_kind_tag` extended to
every normative tag; the MaterializedState decode test populates
page_breaks; four direct regression tests pin each fixed bug; the stale
SetMetadata/score_metadata doc comments now say advisory LWW.
Gates: build/fmt/clippy -D warnings clean; cargo test --workspace green
(533); conformance_suite scale 1 passes. Stages only core/ops/testkit; the
unrelated Agent-I working tree is left untouched.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Levi Neuwirth
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