Extract engine from citation-evidence umbrella (CENG-WP-0001)

Bootstrap @citation-evidence/engine as a standalone TypeScript package
with shared types and engine services copied from the umbrella MVP.
All 89 tests pass with lint and typecheck clean.

workplans/CENG-WP-0001-intent-placeholder.md

@@ -1,31 +1,100 @@
 ---
 id: CENG-WP-0001
 type: workplan
-title: "INTENT placeholder — await extraction from citation-evidence"
+title: "Extract engine from citation-evidence umbrella"
 domain: citation_evidence
 repo: citation-engine
-status: active
+status: done
 owner: codex
 topic_slug: citation_evidence_mvp
 created: "2026-06-21"
-updated: "2026-06-21"
+updated: "2026-06-22"
 state_hub_workstream_id: "ccd217a2-572d-435d-9a29-e0a55b6a4311"
 ---
 
-# CENG-WP-0001 — INTENT Placeholder
+# CENG-WP-0001 — Extract Engine from Umbrella
 
-Umbrella-first MVP: engine code lives in `citation-evidence/src/engine/` and
-`citation-evidence/src/shared/`. This file satisfies ADR-001 workplan structure
-until extraction per `INTENT.md`.
+Extract `citation-evidence/src/shared/` and `citation-evidence/src/engine/` into
+this repository as a standalone TypeScript package (`@citation-evidence/engine`).
 
-## Extraction gate
+Prerequisite: umbrella MVP complete (CE-WP-0001..0008).
+
+## Dependency order
+
+```
+T01 (toolchain scaffold)
+  └─ T02 (copy shared/ + engine/ from umbrella)
+       └─ T03 (conformance reference: wiki/SharedContracts.md)
+       └─ T04 (test + typecheck + lint green)
+```
+
+---
+
+## T01 — Toolchain scaffold
 
 ```task
 id: CENG-WP-0001-T01
-status: wait
-priority: low
+status: done
+priority: critical
 state_hub_task_id: "755e36b7-983d-48e8-af94-fd074db7f745"
 ```
 
-Blocked on citation-evidence MVP stabilization and engine API contract freeze.
-See `citation-evidence/wiki/DependencyMap.md`.
+Deliverables:
+- `package.json` with `test`, `lint`, `typecheck` scripts
+- `tsconfig.json` with `@shared/*` and `@engine/*` path aliases
+- `vitest.config.ts`, `eslint.config.js`, `.nvmrc`
+- Node-oriented `.gitignore`
+
+---
+
+## T02 — Extract shared/ and engine/
+
+```task
+id: CENG-WP-0001-T02
+status: done
+priority: critical
+depends_on: [T01]
+```
+
+Copy the umbrella partitions verbatim:
+- `src/shared/` — domain types, enums, normalization
+- `src/engine/` — services, repos, events, rendering, persistence
+
+No import path changes required; aliases match the umbrella layout.
+
+---
+
+## T03 — SharedContracts conformance reference
+
+```task
+id: CENG-WP-0001-T03
+status: done
+priority: high
+depends_on: [T02]
+```
+
+Copy `wiki/SharedContracts.md` from the umbrella so enum conformance tests
+(`evidence-link.test.ts`) keep a local reference.
+
+---
+
+## T04 — Verification
+
+```task
+id: CENG-WP-0001-T04
+status: done
+priority: critical
+depends_on: [T02, T03]
+```
+
+- `pnpm test` — 89 tests pass
+- `pnpm typecheck` — clean
+- `pnpm lint` — clean (shared/engine boundary enforced)
+
+---
+
+## Follow-up (out of scope)
+
+- Wire `citation-evidence` to consume `@citation-evidence/engine` as a workspace
+  dependency and delete the in-repo copies (CE-WP-0009 or equivalent).
+- Publish package to a registry when sister repos are ready to depend on it.