feat: Phase 0 — monorepo 骨架 + 全表迁移 + FastAPI/Next 骨架 + CI

- uv(workspace) + pnpm monorepo；docker-compose(pg+api+web)
- SQLAlchemy 16 MVP 表 + Alembic 初版迁移(无漂移，users stub)
- FastAPI 骨架：统一错误信封(带 request_id) + structlog + /jobs/:id + OpenAPI
- Next.js 骨架：纸感主题 token + OpenAPI→TS 客户端代码生成(gen:api)
- CI(ruff/mypy/pytest + pg service + alembic 漂移校验)
- 四份设计规格(PRODUCT/UX/ARCHITECTURE/DEV_PLAN) + CLAUDE.md

apps/api/Dockerfile

@@ -0,0 +1,9 @@
+FROM python:3.12-slim
+COPY --from=ghcr.io/astral-sh/uv:latest /uv /usr/local/bin/uv
+WORKDIR /app
+COPY pyproject.toml uv.lock* ./
+COPY packages ./packages
+COPY apps/api ./apps/api
+RUN uv sync --no-dev --frozen || uv sync --no-dev
+EXPOSE 8000
+CMD ["uv", "run", "uvicorn", "ww_api.main:app", "--host", "0.0.0.0", "--port", "8000"]