Browse workspace artifacts by date and file

Traceability

• Spec ID: studio-artifact-workspace-browser
• Status: Ready for Review

Intent

Make Artifacts a first-class view of the currently open project workspace. A reviewer should not have to select one Session before learning which outputs local coding agents changed or delivered. Studio should aggregate the existing, workspace-confined files named by retained change and deliver observations, let the reviewer navigate that set by Date or Files, show the matching Artifact set in an adjacent pane, and render the selected current revision through the existing Artifact View/Canvas boundary.

The open project remains the single workspace authority. Date is observation context, not retained file history: the Artifact renderer continues to show the current exact bytes and revision digest from the workspace.

Acceptance Scenarios

• AC-1: Opening or replacing a project workspace derives one Artifact set from existing files referenced by retained Session change or deliver events. The set is available without selecting a Session, is confined to the canonical workspace root, and rejects symlinks, hard links, directories, missing files, path traversal, and absolute paths outside that root.
• AC-2: /api/artifacts continues to satisfy the public HarnessStudioArtifactCatalogV2 contract and, for a workspace-owned set, adds a Studio-owned navigation projection mapping Artifact ids to bounded Session/date observations. Revision-scoped content, snapshot, build, and hosted-view routes resolve only through the same confined set. A CLI-provided Artifact directory remains a compatibility authority when no project workspace is open.
• AC-3: Artifacts opens directly into a docked three-pane workbench on wide screens: scope navigator on the left, matching Artifact rows in the middle, and the existing Artifact View host on the right. The newest available scope and its first Artifact are selected by default; there is no Select a Session first gate.
• AC-4: Date mode groups observations by day and lists the Sessions that produced existing Artifacts. Files mode presents the same Artifact set as a hierarchical path tree. Selecting a day, Session, directory, or file updates only the adjacent scope; selecting an Artifact updates the renderer. Search filters the middle Artifact list without changing catalog authority.
• AC-5: The UI labels the preview as the current workspace revision and exposes the observed Session/provider/time separately. It does not claim that prior file bytes, cross-Session Artifact identity, or a revision chain were retained.
• AC-6: The title bar owns one project-wide Change workspace action. Replacing or disconnecting the workspace clears the previous Artifact authority and navigation selection. Sessions does not duplicate the change action in its local footer.
• AC-7: At 1440x900, 1024x768, and 390x844, the primary Artifact question and selected preview remain reachable, document-level horizontal overflow is absent, keyboard focus is visible, list/tree controls have accessible names, and browser console/page errors are empty in meaningful populated states.
• AC-8: Observing a source file does not make it executable. Ordinary .tsx and .jsx files use the read-only Source surface and have no build reference. Only the explicit *.canvas.tsx format enters Studio's React Preview or a provider-hosted Canvas lane. Studio-owned Mermaid Preview keeps its renderer dependency closure separate from workspace package imports and works when the open workspace itself contains node_modules.
• AC-9: Recognized text source is syntax-highlighted and padded inside the editor boundary. Unrecognized extensions are sniffed from a bounded byte sample: valid text receives the plain Source surface while binary bytes stay unavailable. A compile or runtime failure automatically exposes the exact highlighted Source revision without hiding the failure status or Retry.

Non-goals

• Scanning every file in the project and calling it an Artifact.
• Retaining historical Artifact bytes, reconstructing old Session outputs, or adding cross-Session Artifact Thread identity.
• Editing, writing back, annotating, or resuming a Session from Artifact View.
• Changing adapter, renderer, Provider, Canvas, sandbox, or content-security selection policy beyond restricting executable TSX to the explicit Canvas format and completing the built-in Mermaid renderer dependency closure.
• Adding a second directory chooser or an Artifact-specific workspace.

Plan and Tasks

1. Derive normalized Artifact observations from workspace Session projections, bind them to the canonical workspace root, and retain only server-private paths plus privacy-safe Session metadata.
2. Allow the Artifact catalog indexer and revision routes to resolve an explicit bounded list of nested workspace-relative files while preserving the legacy single-directory behavior.
3. Add a Studio-owned navigation projection to the workspace catalog and expose the workspace Artifact count through configuration/navigation status.
4. Replace the two-pane Explorer with Date/Files scope navigation, a matching Artifact list, and the existing Artifact renderer pane. Make selection and responsive pane switching keyboard-operable.
5. Move Change workspace to the application title bar and remove the Sessions-local duplicate.
6. Add focused server/model/component/browser coverage, then run package gates, local preview smoke checks, multi-viewport visual review, and Review Readiness Check.
7. Keep ordinary TSX/JSX on the native Source surface, reserve compilation for *.canvas.tsx, and verify the Studio-owned Mermaid renderer against a real repository root whose node_modules is inside the Artifact authority.
8. Make Source the useful failure surface, retain diagnostics in the status boundary, sniff unknown text without decoding binary artifacts, and verify source highlighting and editor padding on representative large files.

Test and Review Evidence

• AC-1/AC-2: focused catalog and server tests with nested paths, duplicate observations, missing files, absolute/outside paths, links, and stale revision requests.
• AC-3/AC-4/AC-5/AC-6: Studio model and browser flows against a workspace provider fixture with multiple days, Sessions, directories, and renderer formats.
• AC-7: Playwright/browser screenshots at 1440x900, 1024x768, and 390x844; keyboard traversal, focus, horizontal overflow, console, and page-error assertions.
• AC-8: registry/catalog assertions for ordinary TSX versus Canvas TSX, a browser Source-only flow, and a real-repository Mermaid compile check that exercises beautiful-mermaid, entities, elkjs, React DOM, and Scheduler.
• AC-9: bounded unknown-text/binary catalog tests plus browser checks for highlighted source, failed-preview fallback, padding, and selection reset. Syntax-highlighting evidence must prove that representative source produces more than one semantic token color in both themes; a highlighted state with only the editor foreground color is a plain-text regression, not a pass.
• Package gates: npm run typecheck, focused Vitest, full packages/harness-studio tests, preview /health and /canvas-module.js, git diff --check, and the Markdown doc-link graph after regenerating it.

Current receipts

• packages/harness-studio: npm test — 40 files, 247 tests passed.
• Playwright: full Harness Studio browser suite — 39 tests passed, including Artifact Host native fallbacks, provider-hosted renderers, and all Artifact Workspace wide/compact/narrow cases.
• Live browser: the 159 KB workbench.css reached highlighted state with padded source layout; the repository Mermaid graph with YAML front matter rendered successfully; no document-level overflow was observed at the three acceptance viewports.
• Syntax-highlighting regression repair: representative MJS source now renders five computed token colors in both dark and light themes instead of marking a single-color foreground as highlighted. The focused highlighter tests pass 4/4 and the Artifact Workspace browser suite passes 3/3, including the multi-color assertion and wide/compact/narrow overflow checks.
• Preview smoke: existing 127.0.0.1:58575 process returned ok from /health and JavaScript from /canvas-module.js.
• Documentation routing: regenerated docs/better-harness-doc-links.mmd; all 8 doc-link graph tests passed.

Risks

• Evidence paths are advisory: retained Session resources may be stale or malformed. Re-resolve every candidate against the canonical workspace and index only its current regular-file bytes.
• Date can be misread as history: keep observed time on the navigation row and current revision in the preview header; do not present a revision timeline without retained bytes.
• Large workspaces: deduplicate observations before hashing, keep the existing Session bound, and index only changed/delivered paths rather than recursively walking the project.
• Concurrent dirty worktree: the pre-existing Commit-view files and their overlapping stylesheet edits are outside this scope. Preserve those changes and edit only the Artifact-owned CSS region.
• Executable-source confusion: file extension is not evidence that code is intended to run. Require the explicit Canvas suffix before attaching a build route; keep built-in renderer dependencies on a separate trusted closure.