Refactor code for improved readability and consistency

- Cleaned up whitespace and formatting in various files including http.py, language.py, logger.py, safe_exec.py, and SQL migration scripts.
- Consolidated import statements and removed unnecessary blank lines.
- Updated logging configuration for better clarity.
- Enhanced the safe execution code with improved error handling and logging.
- Removed commented-out code and unnecessary variables in backfill_zero_trades.py and other scripts.
- Added a pyproject.toml for Ruff and Vulture configuration.
- Introduced requirements-dev.txt for development dependencies.
- Removed commented-out stock entries in init.sql for cleaner migration scripts.

docs/README_CN.md

@@ -91,7 +91,7 @@ docker-compose up -d --build
 > - 启动：
 >   `docker-compose up -d --build`
 
-> **Windows PowerShell**: 
+> **Windows PowerShell**:
 > - 复制后端配置：
 >   `Copy-Item backend_api_python\env.example -Destination backend_api_python\.env`
 > - 如果需要更多高级配置，直接查看这个文件下半部分的 “Advanced / rarely changed”：