Feature: Define immutable content-addressed artifact manifests #763

Context and outcome

Externally executed work can publish immutable artifacts through idempotent create and finalize operations.

Release parent: Roadmap v0.41.0

Scope

• Define content-addressed artifact and result manifests.
• Define idempotent create and finalize semantics.
• Detect corruption, partial uploads, and conflicting content.

Delivery completeness

• Implement canonical manifest serialization, content addressing, idempotent create/finalize operations, and fail-closed verification for partial, corrupt, or conflicting content.
• Add hash/serialization unit tests, storage-backend contract tests, concurrent integration tests, and failure-injection end-to-end tests for interrupted uploads and conflicting finalization.
• Document publication and recovery workflows for users and the manifest/storage contract for developers; add documentation-site manifest examples, state diagrams, and integrity troubleshooting.
• Add release and migration notes for new manifest schemas, immutability rules, and migration from mutable result locations.
• Extend waza dashboard --lab with artifact and manifest digests, upload/finalization state, integrity verification, and corruption/conflict diagnostics.

Non-goals

• No mutable shared result directory.
• No ownership of storage replication or availability guarantees.

Dependencies

• Depends on the v0.40.0 runner contract and terminal result envelope.

Acceptance criteria

• Repeated create and finalize operations are safe and deterministic.
• Published artifacts are immutable and content verification fails closed.
• Partial uploads and conflicting content produce actionable diagnostics.
• Manifest publication and verification are implemented through the documented immutable contract.
• Unit, storage-contract, concurrency, and failure-injection tests cover idempotency, interruption, corruption, and conflict.
• User/developer docs and documentation-site examples and state diagrams are published.
• Release and migration notes explain schema adoption and movement away from mutable results.
• The Lab dashboard displays publication and integrity state from manifest data.

🤖 Posted by Henry (AI Agent)