🎉 feat: 建立阶段 0 工程骨架与 OpenAPI 契约机器化（WP-01 起步）

- Makefile：统一命令入口（backend/engine/docker/openapi/generate，含 make help）
- backend：FastAPI + uv 最小工程，统一错误体（契约第 7 节）、ADR-015 平台 ID 生成与校验（uuid-utils）；pytest 7 项、ruff、mypy strict、启动冒烟全部通过
- engine：灵台引擎 C++23/CMake 骨架，按 Lingtai C ABI 契约实现 lingtai.h（13 个 HjStatus、版本协商、句柄表防二次释放、线程局部错误上下文）；doctest 5 用例通过，nm 验证仅导出 hj_* 符号
- openapi：OpenAPI 3.1 单一真源初始版（错误体/分页/Money/首批平台 ID/ContentBlock 全 21 类型/流事件 envelope），Redocly lint 0 错误、bundle 通过
- frontend：Next.js 最小骨架，openapi-typescript 生成 API 类型并通过 strict tsc
- docker：hunjing-postgres（pgvector:17）compose；.env.example 与 config 示例
- ADR-025：登记测试与契约工具链（doctest/libFuzzer/Redocly/openapi-typescript/uuid-utils）
- desktop：Tauri v2 占位与初始化说明（WP-10 启动）

backend/pyproject.toml

@@ -0,0 +1,46 @@
+[project]
+name = "hunjing-backend"
+version = "0.1.0"
+description = "Hunjing 后端服务（FastAPI 模块化单体）"
+requires-python = ">=3.12"
+dependencies = [
+    "fastapi>=0.115",
+    "uvicorn[standard]>=0.32",
+    "pydantic>=2.9",
+    "pydantic-settings>=2.6",
+    "sqlalchemy>=2.0",
+    "alembic>=1.14",
+    "asyncpg>=0.30",
+    "uuid-utils>=0.10",
+]
+
+[dependency-groups]
+dev = [
+    "pytest>=8.3",
+    "pytest-asyncio>=0.24",
+    "httpx>=0.27",
+    "ruff>=0.8",
+    "mypy>=1.13",
+]
+
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[tool.hatch.build.targets.wheel]
+packages = ["app"]
+
+[tool.ruff]
+line-length = 100
+target-version = "py312"
+
+[tool.ruff.lint]
+select = ["E", "F", "I", "UP", "B", "ASYNC"]
+
+[tool.mypy]
+python_version = "3.12"
+strict = true
+
+[tool.pytest.ini_options]
+asyncio_mode = "auto"
+testpaths = ["tests"]