> **Plain-language companion:** [v0.87.4.md](v0.87.4.md)

## v0.87.4 — Stateful and Metamorphic Correctness

**Status: Complete.** Derived from [ROADMAP.md](../ROADMAP.md).

The release makes the existing DVM correctness harness choose mutations from
known source state and compare semantically equivalent histories. It keeps
PostgreSQL as the independent oracle and records changed leaves and mutation
intents so boundary coverage is visible.

### Correctness

| ID | Title | Status |
|----|-------|--------|
| COR-10 | State-directed mutation planner | ✅ Done |
| COR-11 | Multi-source mutation histories | ✅ Done |
| COR-12 | Metamorphic correctness families | ✅ Done |

### Release plumbing

| ID | Title | Status |
|----|-------|--------|
| REL-1 | Version and release artifact synchronization | ✅ Done |

### Recommended implementation order

1. Keep state selection pure and unit-testable.
2. Add deterministic multi-source scenario metadata and exact checks.
3. Add the metamorphic family inventory and batching E2E case.
4. Synchronize versioned release artifacts and run the release gates.

### Implementation Status

| ID | Title | Status |
|----|-------|--------|
| COR-10 | State-directed mutation planner | ✅ Done |
| COR-11 | Multi-source mutation histories | ✅ Done |
| COR-12 | Metamorphic correctness families | ✅ Done |
| REL-1 | Version and release artifact synchronization | ✅ Done |

### Exit Criteria

- [x] One, two, and all-leaf mutation cycles are represented.
- [x] Group and outer-join boundary transitions are explicit intents.
- [x] Every planned mutation verifies an effective target in the pure model.
- [x] At least six metamorphic families are enumerated.
- [x] Batching invariance uses the exact direct-query oracle.
- [x] `just fmt` passes.
- [x] `just lint` passes with zero warnings.
- [x] Version synchronization and adjacent upgrade checks pass.
