MCR Core v0.1.0

MCR Core v0.1.0 is the first release of the runtime-neutral Go library specified and accepted in #10.

Delivered

• #11: concrete Workspace seam with distinct Create/Open and Submit/Query/Replay/Verify operations.
• #12–#14: the complete closed 12-Kind native Task Fact vocabulary: Task, Run, Registered Input, Artifact, Claim, Source Reference, Evidence Link, Review, Approval, Policy Decision, Delivery, and explicit Opaque Fact.
• #15: private Workspace storage, strict sealed JSONL, non-blocking OS locks, crash-safe atomic replacement, permission preservation, and filesystem containment.
• #16–#17: read-only legacy compatibility with deterministic Query/Replay and explicit sealed_valid, unsealed, partial_invalid, and sealed_invalid verification outcomes; neutral fixtures, semantic goldens, hash vectors, CLI conformance, and malformed-history diagnostics.
• #19–#30: mandatory parent-review hardening for descriptor-relative root/storage/ledger identity, full storage lifecycle races, bounded streaming history/cache/Submit processing, arbitrary Opaque JSON numbers, additive and under-bound legacy preservation, invalid-history result retention, exact record counts, validation-to-commit identity, and semantic legacy Task scope.

The built-in CLI remains a thin JSON adapter with exactly submit, query, replay, and verify commands.

Verification

The immutable tag points to 1dc14341fcedf52960584480e8b158fd05b8a22f. From a clean detached checkout:

go test ./... -count=1
go vet ./...
go build -o /tmp/mcr-core-v0.1.0 ./cmd/mcr

All passed, and the checkout remained clean with no generated sidecars.

Boundaries

This release is a runtime-neutral library and CLI. It does not execute agents, interpret Pack or scenario content, expose HTTP/gRPC services, maintain a mutable product projection, convert or rewrite legacy histories, or perform downstream Agent-lab adoption. Agent-lab pinning, compatibility CI, canary adoption, and writer cutover remain separate downstream work.