dsh-asset-split: Asset Allocation Plugin

`dsh-asset-split` is a tooling plugin for asset allocation calculations maintained by uckkk. It is implemented in pure Node.js and requires no network dependencies. It provides local asset allocation calculation capabilities, making it suitable for offline use in DSH workflows. The plugin depends on `@deepseek-ai/cordis` and `@deepseek-ai/dsh-tools`, and can be invoked directly in a session after installation. Users should be mindful of permission security and dependency version compatibility.