The wave-1 contract surface: everything engine-blind that waves 2-6
implement against. No engine bodies, no facade behavior logic.
- src/backend.rs: the pub(crate) Backend trait — seven methods +
put_staged, opaque byte keys/values, size metadata-only, list
complete-and-well-formed, virgin-store reads as no-ops (ADR-003,
ADR-008); the ReadCursor/StagingCursor I/O seams with the read_range
slice-digest convention (ADR-006) at one seam; unit tests against
both body-family doubles, a test-double engine, and the stage-hygiene
invariant's two forms (discard; commit failure self-discards).
- src/gc.rs: the engine-state companion seam as EngineWindowState /
EngineFleetState — ADR-012 §5's applicability table expressed
structurally (no dead machinery); JointTx ownership rule pinned in
the signature (store holds the tx; engine contributes mechanics).
- src/facade.rs: EntryMeta, Pin, Batch, SweepReport, GcAbortCause
(x3, #[non_exhaustive]), PinState with lifecycle contracts
(ADR-005, ADR-012 §1); re-exported from lib.rs.
- Design points pinned for the wave-1 review gate in
tasks/core-trait-and-types.md: pub(crate) trait visibility,
associated-type put-form shapes, AFIT + associated types (no dyn).
Verification: cargo test (26 lib + 3 git-interop), cargo test
--all-features, clippy --all-targets -D warnings (default and
--all-features), cargo fmt --check, cargo doc --no-deps — all green.
glm-5.3-flash
0547c17876