fix(sandbox: Suppress mypy attr-defined error on Windows for resource.setrlimit

[Abdurrafay19]

This pull request improves the design, documentation, and robustness of the patchwork/tools/sandbox.py module, focusing on subprocess isolation, logging, and cross-platform compatibility. The most important changes are:

Design and Documentation Improvements:

• Added a clear summary of design goals to the module docstring, emphasizing subprocess timeouts, use of temporary directories for generated code, output truncation to protect LLM context, and structured logging practices.

Code Robustness and Cross-platform Compatibility:

• Updated the _limit_subprocess_memory function to include a type: ignore comment for mypy, clarifying that the resource module is only used on POSIX systems and ensuring type checking compatibility on Windows.

Code Organization:

• Renamed the constants section header to "Tunables" for clarity and better organization.…etrlimit (Windows has no resource module)