Fourth broad-K0 subsystem group — three value-typed LWW field-overwrite ops, one
per settings cluster (additive: OperationKind variants 21-23; framework frozen):
- SetMetadata { metadata: ScoreMetadata } — overwrite the score-singleton
metadata (title/composer/copyright); concurrent differing ⇒
StructuralFieldCollision.
- SetMetricGrid { region, grid: Option<MetricGrid> } — overwrite a region's
default metric grid (LWW keyed by region; concurrent differing ⇒ collision).
- SetUserPageBreak { region, anchor, present } — the page-break sibling of
SetUserSystemBreak: a canonical LWW advisory.
- core: expose ScoreMetadata + MetricGrid via CanonicalValue (no new byte layout
— they already have whole-score Codec impls).
- SetMetadata / SetMetricGrid mirror the modify ops: the resolved value lives in
the graph (reduce_onto), with new last_metadata / last_metric_grid LWW working
state for concurrent-differing detection; MaterializedState records only the
effect and conflict.
- SetUserPageBreak mirrors SetUserSystemBreak's canonical advisory: a new
MaterializedState.page_breaks map (encode + decode added, parallel to breaks),
plus the graph's region user_page_breaks.
Migration: v1-native (no lossy v0 predecessor) -> project/migrate by identity;
the round-trip identity test now covers all four M2 groups.
Coverage:
- testkit operation_payload + ops fuzz gen_payload emit the three kinds, so the
convergence / determinism / migration-equivalence and MaterializedState
decode-roundtrip gates exercise them (incl. page_breaks) at scale.
- reduce_onto graph tests: the three settings materialize in graph and ledger
(metadata title, region default metric grid, region user page break +
MaterializedState.page_breaks), invariant-clean; plus a concurrent-differing
SetMetadata conflict test.
Gates: build/fmt/clippy -D warnings clean; cargo test --workspace green (519);
conformance_suite scale 1 passes. Catalog sections + DECISIONS for the M2 groups
land in M2e per the staged plan. The unrelated Agent-I working tree is left
uncommitted; this commit stages only core/ops/testkit.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Levi Neuwirth
1e4ab24779