Narrow the Studio artifact catalog contract

Traceability

• Spec ID: artifact-workspace-model
• Status: Implemented

Intent

Replace the unpushed, cross-domain artifact-workspace programming abstraction with the smallest contract that Harness Studio actually runs: a read-only, versioned Artifact Catalog response shared by the server and both React consumers.

The catalog must have one format registry, bind every public content reference to exact bytes, preserve the existing Canvas viewer priority, and keep active artifact bytes safe even when their raw content URL is opened directly. Generic planning, execution, verification, and driver contracts must not be published until a production domain needs them.

Acceptance Scenarios

• AC-1: Artifact kind and mediaType derive from one extension registry. The raw content endpoint returns the same media type advertised by the descriptor for PDF, Office, Lottie, HTML, SVG, source, and image formats.
• AC-2: /api/artifacts returns an explicit HarnessStudioArtifactCatalogV1 response. Each descriptor contains one required \{ uri, mediaType, digest \} content reference; it has no unused role or optional inline-data branch.
• AC-3: Both React consumers import that response type. Artifact View reads artifact.uri, uses the digest as its content identity, and does not rebuild content URLs from ids.
• AC-4: Presentation is joined to catalog entries by id while each entry is projected, never by parallel-array position. Directory failures remain a bounded 404; internal contract violations return a distinct 500 status.
• AC-5: Raw HTML and SVG responses are non-sniffable attachments with a deny-by-default CSP. Studio previews SVG by fetching its declared content URI and placing the text in a sandboxed, network-denied srcdoc, so direct raw navigation never becomes the preview execution boundary.
• AC-6: The package no longer exports or packs @qoder-ai/harness-studio/artifact-workspace; the generic runtime and its test-only driver are removed before the two local commits reach origin/main.
• AC-7: Existing direct/Canvas renderer priority, path confinement, symlink rejection, Office sidecars, and sandboxed Canvas runtime behavior remain unchanged.

Non-goals

• Defining a cross-domain mutation, transaction, scenario, or verification API.
• Adding artifact authoring controls or a second Artifact classification model.
• Unifying packaging artifacts, checkpoint evidence references, and Studio run outputs under one vocabulary; those are separate namespaces until a real integration requires a bridge.
• Publishing packages, changing versions, or altering release metadata.
• Adding filesystem watching, retention, or a (size, mtime) digest cache in this contract correction. Full re-hashing remains a measured follow-up risk.

Plan and Tasks

1. Replace src/artifact-workspace/ with a browser-safe internal catalog response type and remove the package subpath.
2. Merge extension kind/media mappings into one registry and project complete typed descriptors from each entry plus its id-bound presentation.
3. Consume the shared response and content reference in App.tsx and RunView.tsx; keep the catalog revision visible to React state.
4. Use the catalog media resolver in the content route, classify directory and contract failures separately, and harden active content response headers.
5. Add behavioral tests for response shape, id binding, media parity, active content safety, client rendering, removed package exports, and regressions.

Test and Review Evidence

• AC-1/AC-2/AC-4/AC-5/AC-7: 60 focused catalog, viewer, and server behavior tests passed across three files, including exact MIME parity and active response headers.
• AC-3/AC-5: all 17 Playwright tests passed. A route-level test rewrites one descriptor URI and proves React follows it; the SVG flow verifies sandboxed srcdoc, raw attachment/CSP headers, and no parent execution.
• AC-6: typecheck/build passed. npm pack --dry-run --json --ignore-scripts contained zero dist/artifact-workspace/ files, and importing the removed subpath failed with ERR_PACKAGE_PATH_NOT_EXPORTED.
• Package gate: 124 tests passed across 18 files. The repository-wide run passed 1432 of 1433 tests; its sole failure was an unrelated fixed 10-second CLI-help timeout for commit-session-link render-session --help, and the isolated behavior rerun passed in 5.41 seconds.
• Diff hygiene and exact commit/push readback are recorded at delivery.

Risks

• Raw artifact access is intentionally CORS-readable by the opaque Canvas viewer. CSP, attachment disposition, MIME parity, and renderer sandboxing must therefore remain independent, tested layers.
• Exact-byte SHA-256 is still recomputed on each catalog request. The configured directory is operator-controlled and bounded, but a cache needs a separate invalidation contract rather than an untested optimization in this patch.