feat: extract review-workspace slice into @citation-evidence/work (CWORK-WP-0001)

Establishes citation-work as the standalone home of the review workspace,
migrated out of the citation-evidence umbrella app.

- Package/tooling scaffold: package.json, tsconfig, vite/vitest/eslint configs
  with eslint-plugin-boundaries enforcing engine/anchor/source-only imports
- Providers/hooks: EngineProvider, SessionProvider + use* hooks (T02)
- Panes: CollectionList, ViewerShell, EvidenceSidebar (T03/T04/T05)
- Capture/edit: InlineCaptureForm, EvidenceFormBody; UploadDropzone owned here
- ReviewShell: repo-owned three-pane layout with an upload slot seam
- Tests: CollectionList, InlineCaptureForm capture flow, EvidenceSidebar
  export/edit/activation (11 tests, all green)
- Anchor consumed as @citation-evidence/evidence-anchor package; @source kept
  on the umbrella facade for its local viewer-url policy
- Docs (README/SCOPE) refreshed; deferred gaps recorded

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

README.md

@@ -2,16 +2,78 @@
 
 A document review workspace — the React surfaces for the review workflow:
 collection list, viewer shell, evidence sidebar, annotation create flow,
-form-binding side-by-side layout.
+and review-oriented upload/navigation shell.
 
-## MVP status: INTENT only
+Published as the `@citation-evidence/work` package and consumed by the
+`citation-evidence` umbrella app's review mode.
 
-During the citation-evidence MVP, code lives upstream in
-[`citation-evidence`](../citation-evidence/) under `src/work/`. This repo
-currently holds `INTENT.md` describing what will move here. Contract
-changes belong in
-[`citation-evidence/wiki/SharedContracts.md`](../citation-evidence/wiki/SharedContracts.md),
-not here.
+## Current state
 
-Per the dependency map, work depends on `shared/`, `engine/`, `anchor/`,
-and `source/` — and **may not** import from `binder/`.
+This repo is now the **code of record** for the review workspace. The slice was
+extracted from the umbrella app under `CWORK-WP-0001`; `citation-evidence` no
+longer carries a local `src/work/` implementation and instead depends on this
+package (its `@work` alias resolves here).
+
+Package surface (`src/work/index.ts`):
+
+- **Shell:** `ReviewShell` — the three-pane review layout (collection · viewer · sidebar)
+- **Panes:** `CollectionList`, `ViewerShell`, `EvidenceSidebar`
+- **Capture/edit:** `InlineCaptureForm`, `EvidenceFormBody`
+- **Upload:** `UploadDropzone` (also the default `ReviewShell` upload slot)
+- **Providers/hooks:** `EngineProvider`, `SessionProvider`, and the associated
+  `use*` hooks; `useExportEvidence`; `useDebugFlag`
+
+### Upload seam decision (T03)
+
+`UploadDropzone` is owned by this package — it depends only on `@source` and the
+local engine/session hooks, so the shell renders a complete review surface with
+no umbrella-local imports. `ReviewShell` still exposes an `upload` slot so a
+consumer can substitute its own affordance; when omitted, the package default is
+used.
+
+## Boundary
+
+`citation-work` depends on:
+
+- [`@citation-evidence/engine`](../citation-engine/)
+- [`@citation-evidence/evidence-anchor`](../evidence-anchor/)
+- `@source` (PDF ingestion + viewer-url policy)
+
+It may **not** import from binder-owned or umbrella-app-owned review-to-form
+code. The dependency edges are enforced by `eslint-plugin-boundaries` in
+`eslint.config.js`.
+
+## Alias / extraction notes
+
+`citation-engine` and `evidence-anchor` are extracted sibling packages and are
+consumed by their package names. `@source/*` still resolves into the umbrella's
+`src/source` façade because that façade owns the local `viewer-url` policy that
+is not part of the extracted `evidence-source` package. This is the one
+remaining transitional edge; see the deferred list below.
+
+## Deferred after this extraction
+
+The following were intentionally **not** part of `CWORK-WP-0001` and remain for a
+subsequent workplan slice (see the workplan's "Deferred After This Workplan"
+section for the authoritative list):
+
+- collection search / filter UX,
+- document review-status interactions,
+- evidence-item status / tagging / filtering UX,
+- binder-integrated review-to-form workflows,
+- new viewer/document-format features beyond the current PDF slice,
+- retiring the `@source` façade edge once a `viewer-url` home is decided (either
+  a small local module here or an `evidence-source` addition).
+
+## Verification
+
+```bash
+pnpm install
+pnpm typecheck
+pnpm lint
+pnpm test
+```
+
+## Workplan
+
+- [CWORK-WP-0001](workplans/CWORK-WP-0001-extract-review-workspace.md)