dsh-takeout-tip: Precise Takeout Fee Calculation Tool

The `dsh-takeout-tip` plugin introduced by DeepSeek Harness (DSH) aims to provide agents with the ability to calculate delivery tips accurately without making network requests. This pure Node.js-based tool registers the `takeout_tip` tool and can generate detailed results based on input parameters. Before use, the version requirements for `@deepseek-ai/cordis` and `@deepseek-ai/dsh-tools` must be met, making it suitable for direct invocation in scenarios that require handling delivery-tip logic.