chore: P1 工程化工具链

- pyproject.toml：pytest/black/isort/mypy 统一配置
- requirements-dev.txt：测试与代码规范开发依赖
- .flake8 / .editorconfig：PEP8 与编辑器统一
- .pre-commit-config.yaml：提交前钩子
- Makefile：常用命令集
- .env.example：环境变量模板（76 键）
- tests/：pytest 骨架 + R 响应格式冒烟测试

Co-Authored-By: Claude <noreply@anthropic.com>

.pre-commit-config.yaml

@@ -0,0 +1,39 @@
+# ============================================================
+# pre-commit 钩子配置
+# 安装：pip install -r requirements-dev.txt && pre-commit install
+# 手动全量运行：pre-commit run --all-files
+# ============================================================
+repos:
+  # ---- 通用钩子 ----
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v5.0.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml
+      - id: check-json
+      - id: check-merge-conflict
+      - id: debug-statements
+      - id: detect-private-key
+      # ip2region.xdb 约 10MB，放行大文件
+      - id: check-added-large-files
+        args: ["--maxkb=12000"]
+
+  # ---- Python 格式化：black ----
+  - repo: https://github.com/psf/black
+    rev: 24.10.0
+    hooks:
+      - id: black
+        args: ["--line-length", "120"]
+
+  # ---- import 排序：isort ----
+  - repo: https://github.com/PyCQA/isort
+    rev: 5.13.2
+    hooks:
+      - id: isort
+
+  # ---- 静态检查：flake8 ----
+  - repo: https://github.com/PyCQA/flake8
+    rev: 7.1.1
+    hooks:
+      - id: flake8