Connect PowerContext Memory Service to DeepSeek Harness via powercontext-dsh

### 翻译结果（符合技术文档规范）： powercontext-dsh is an Apache-2.0 licensed DeepSeek Harness memory plugin maintained by knqiufan. It connects to a running PowerContext Server via HTTP, providing recall, memory, handover, experience and skill capabilities without embedding storage or using MCP. This article verifies the installation commands, pc_* tools, `/pc` command, configuration items and security boundaries against the community directory page and GitHub repository.