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>

AGENTS.md

@@ -2,7 +2,7 @@
 
 ## Repo Identity
 
-**Purpose:** Review workspace UI, annotation UX, evidence sidebar. Depends on engine, anchor, source — NOT on binder. INTENT-only during umbrella-first MVP.
+**Purpose:** Review workspace UI, annotation UX, evidence sidebar. Depends on engine, anchor, source — NOT on binder. Standalone package scaffold exists; implementation extraction is in progress under `CWORK-WP-0001`.
 
 **Domain:** infotech
 **Repo slug:** citation-work