feat(studio): ship AgentReact and a project-first workbench

.gitignore

@@ -23,6 +23,9 @@ dev/terminal-demo/*.cast
 /harness-qoder-profile-evidence/
 design-qa.md
 
+# Linked AgentReact bundles written by the Artifact Runtime tests.
+packages/harness-studio/test/.artifacts/
+
 # Local Artifact View scratch decks and their inspection dumps.
 /*.pptx
 /*.pptx.inspect.ndjson

docs/specs/2026-08-27-studio-project-first-workbench.md

@@ -0,0 +1,155 @@
+# Make projects the Studio workbench scope
+
+## Traceability
+
+- Spec ID: studio-project-first-workbench
+- Status: Implemented
+- Related decision: [Developer Experience System](../adrs/developer-experience-system.md)
+- Design contract: [Harness Studio visual system](../../DESIGN.md)
+
+## Intent
+
+Make Harness Studio project-first: a persistent left sidebar selects the active
+project, and one shared workbench shell hosts every project-scoped View. Project
+selection must be fast and explicit without forcing Sessions, Inputs, Commits,
+Artifacts, Debugger, Compare, or Customizations to duplicate project chrome or
+adopt one shared domain model.
+
+The UI term **Project** identifies a remembered local or imported project entry.
+The server term **workspace** remains the materialized filesystem and execution
+authority for the active Project. Configured Inspector, experiment, evidence,
+and compatibility Artifact inputs remain independent **Sources** and must not be
+presented as if they belong to the selected Project.
+
+## Acceptance Scenarios
+
+- **AC-1:** At wide layout, Studio shows a persistent Projects sidebar and one
+  adjacent workbench. The active Project expands one shared View navigation for
+  Overview, Customizations, Inputs, Sessions, Commits, Artifacts, Debugger, and
+  Compare; inactive Projects remain compact rows and do not duplicate the View
+  navigation.
+- **AC-2:** Opening a local directory registers an opaque Project descriptor,
+  activates its freshly discovered workspace snapshot, and exposes only the
+  Project id, label, revision, availability, and bounded counts to the browser.
+  Native absolute paths remain server-only.
+- **AC-3:** Activating a remembered Project re-runs workspace discovery, replaces
+  the active workspace atomically, increments a monotonic Project revision, and
+  refreshes project-scoped configuration, Sessions, Inputs, Git, Artifacts,
+  Customizations, Compare, and default Debugger context. A cancelled or failed
+  activation leaves the previous active Project usable.
+- **AC-4:** Project routes encode the opaque Project id and View. Reload,
+  browser back, and browser forward restore the active Project and View when the
+  Project is still registered. Selecting another Project preserves the current
+  View when possible and otherwise renders that View's honest unavailable state.
+- **AC-5:** The shared shell owns product identity, Project/View context, theme,
+  source selection, Project opening, and Project removal. Feature Views may own
+  one local toolbar and their internal panes, but they do not repeat the active
+  Project title or workspace change/disconnect controls.
+- **AC-6:** Compare distinguishes current-Project Session comparison from
+  configured experiment and frozen evidence Sources. A fixed experiment
+  checkpoint is labelled as read-only context and is not rendered as a fake
+  Project selector.
+- **AC-7:** A live run captures the active Project id and revision at request
+  start. Switching the UI Project cannot silently retarget an already-started
+  run; the visible run context continues to identify its bound Project.
+- **AC-8:** At 1440x900, 1024x768, and 390x844, the primary Project and active
+  View remain obvious, the sidebar becomes a keyboard-operable overlay when
+  compact or narrow, focus is visible, document-level horizontal overflow is
+  absent, and browser console/page errors are empty in populated states.
+- **AC-9:** Existing feature behavior remains reachable: Session inspection and
+  comparison, Input trace and Intent analysis, Git history and patches, Artifact
+  browsing and preview, customization analysis, Debugger runs, ACP permissions,
+  Compare Simple/Advanced paths, and frozen evidence rendering.
+
+## Non-goals
+
+- Loading every remembered Project's full Session, Git, Artifact, or Inspector
+  model into memory simultaneously.
+- Merging feature-specific evidence, run, Artifact, Git, or experiment models
+  into a universal Project or View IR.
+- Claiming that configured experiment, evidence, Inspector, or compatibility
+  Artifact Sources belong to the active Project without explicit binding.
+- Adding a remote project service, authentication, collaboration, cloud sync,
+  host adapter, or repository mutation workflow.
+- Persisting remembered Projects across Studio server restarts in this change;
+  the Project catalog is process-local and can gain a server-private durable
+  store under a separately reviewed contract.
+
+## Plan and Tasks
+
+1. Add browser-safe Project descriptor and snapshot contracts with opaque ids,
+   monotonic revisions, and pure route/view models.
+2. Replace the single open-workspace route flow with a process-local Project
+   catalog that registers local/imported workspaces, activates one materialized
+   workspace at a time, preserves the previous Project on failure, and retains
+   compatibility aliases for current workspace clients.
+3. Split the React application shell into Project sidebar, context bar, View
+   viewport, shared states, and a pure View registry. Key project-scoped Views
+   by Project id and revision rather than an unlabelled workspace counter.
+4. Move Project opening/removal and Project identity out of Sessions and other
+   feature components. Keep feature-specific filters, tabs, actions, and dense
+   workbench panes local.
+5. Make Compare scope explicit and replace its one-option Current Project
+   select with a read-only checkpoint context.
+6. Add model, server, and Playwright coverage for registration, A/B activation,
+   failure preservation, path privacy, routes, keyboard behavior, responsive
+   layout, stale UI state, and existing feature reachability.
+7. Run package build/typecheck/tests, focused browser suites, preview health and
+   module smoke, console/error inspection, three-width screenshots, document
+   link validation, and a Review Readiness Check.
+
+## Test and Review Evidence
+
+- **AC-1/AC-4/AC-5/AC-8:** pure shell/route tests plus Playwright Project A to
+  Project B switching at 1440x900, 1024x768, and 390x844; assert one visible View
+  navigation, focus restoration, no document overflow, and screenshots.
+- **AC-2/AC-3:** server tests for Project listing/opening/activation/removal,
+  cancelled and failed discovery, revision increments, same-origin mutation,
+  imported-directory lifetime, and responses that never serialize native paths.
+- **AC-6:** Compare model/browser checks distinguish Sessions, Bench, and frozen
+  results and assert the checkpoint context is not an interactive Project select.
+- **AC-7:** server and browser checks record the Project binding used by a live
+  default-workspace run and prove later Project selection does not change it.
+- **AC-9:** existing Harness Studio package and browser suites remain green,
+  with selector updates limited to the shared chrome contract.
+- Required commands:
+  - `npm run build -w @qoder-ai/harness-studio`
+  - `npm run typecheck -w @qoder-ai/harness-studio`
+  - `npm test -w @qoder-ai/harness-studio`
+  - `npm run test:browser -w @qoder-ai/harness-studio`
+  - `npx vitest run test/skills-docs/doc-link-graph.test.mjs`
+  - `node scripts/doc-link-graph/cli.mjs skills/better-harness`
+  - `npm run preview`, then smoke `/health` and `/canvas-module.js`
+- Risk: Project switching can cross-contaminate in-flight client reads. Mitigate
+  with Project id/revision keys, effect cancellation, atomic activation, and
+  response binding checks.
+- Risk: a live run could execute in a different directory than the visible
+  Project. Mitigate by capturing Project id/revision/cwd once at run start and
+  retaining that binding in the run projection.
+- Risk: configured Sources can be mistaken for Project evidence. Mitigate with
+  explicit scope labels and independent source selection.
+- Risk: the additional sidebar can squeeze dense workbenches. Mitigate with the
+  existing wide/compact/narrow boundaries, overlay navigation below 1080px, and
+  locally scrolling panes.
+
+## Review Evidence
+
+- `npm run build -w @qoder-ai/harness-studio` passed.
+- `npm run typecheck -w @qoder-ai/harness-studio` passed.
+- `npm test -w @qoder-ai/harness-studio` passed: 61 files, 472 tests.
+- `npm run test:browser -w @qoder-ai/harness-studio` passed: 50 Playwright
+  scenarios, including Project A/B switching, browser back/forward restoration,
+  live-run Project binding, keyboard traversal, clean browser errors, and
+  screenshots at 1440x900, 1024x768, and 390x844.
+- `npm run check` passed under the repository-supported Node 24 runtime: 104
+  root test files (1545 passed, 2 skipped), generated language sources, 173
+  Harness tests, 31 Harness UI tests, 472 Harness Studio tests, and npm/runtime
+  package verification. The host's default Node 26 is outside the declared
+  `>=22.20.0 <25.0.0` engine range and cannot run Langium generation.
+- `npx vitest run test/skills-docs/doc-link-graph.test.mjs` passed: 8 tests.
+- `node scripts/doc-link-graph/cli.mjs skills/better-harness` regenerated the
+  graph with no resulting tracked diff.
+- `npm run preview` failed fast before binding a port because this machine has
+  no Canvas SDK runtime and neither `CANVAS_SDK_MEDIA_DIR` nor
+  `CANVAS_SDK_ROOT` is configured. Consequently `/health` and
+  `/canvas-module.js` could not be claimed as live Preview evidence.