# Task 002: Shared Domain Contracts

Development description: Implement the shared domain schema package that defines workflow statuses, role names, API DTOs, and validation contracts used consistently by backend, frontend, runner, and tests.

## Implementation Details

- Define canonical enums for:
  - Roles: `ADMIN`, `EDITOR`.
  - Article workflow statuses from `ARTICLE_BRIEF_CREATED` through `PUBLISH_COMMIT_CREATED`.
  - Agent job statuses and error categories.
  - Claim support statuses and risk levels.
  - Publishing statuses.
- Define shared request/response schemas for:
  - Article create/list/detail.
  - Target site config.
  - Script/config version.
  - Agent job.
  - Research artifact manifest.
  - Plan, draft, evidence, asset, review, and publish commit summaries.
- Choose one source of truth for validation:
  - Recommended implementation: Pydantic models in backend plus generated OpenAPI client/types for frontend.
  - Shared package may hold OpenAPI schema snapshots and TypeScript types generated from backend.
- Add schema validation tests for representative valid and invalid payloads.

## Public Interface

- Backend exposes OpenAPI JSON with the canonical contracts.
- Frontend imports generated API types instead of duplicating DTO shapes.
- Runner consumes backend contracts for job input/output validation.

## Acceptance Criteria

- [ ] TDD pre-requirement: before implementation, write a failing contract test for one externally visible DTO and one invalid payload; proceed one schema at a time and record red-green evidence in `Result`.
- [ ] Workflow status transitions use shared constants rather than string literals spread across apps.
- [ ] Role names are exactly `ADMIN` and `EDITOR`.
- [ ] Generated frontend types match backend OpenAPI.
- [ ] Contract tests fail on missing required fields and invalid enum values.
- [ ] Runner job output schemas can be validated without importing frontend code.

## Verification

- Run backend schema tests.
- Generate frontend API types.
- Run a typecheck in frontend against generated types.

## Result

- Status: Pending execution.
- TDD plan: To be filled during execution.
- Red evidence: To be filled during execution.
- Green evidence: To be filled during execution.
- Refactor notes: To be filled during execution.
- Verification output: To be filled during execution.