dsh-appliance-life: Precise Appliance Lifespan Calculation Plugin

The `dsh-appliance-life` plugin for DeepSeek Harness (DSH), maintained by uckkk, focuses on accurate appliance lifespan calculations and recommendations. Built entirely with Node.js, it has no network dependencies. It depends on a specific version of DSH, enabling developers to install it via the command line and invoke tools directly within a session to assess appliance usage status.