superfly/sprites-deepseek-plugin: Using Sprites for Environment Isolation in DeepSeek Harness

`superfly/sprites-deepseek-plugin` is a DeepSeek Harness (DSH) plugin designed to integrate isolated and persistent Linux environments (Sprites) into DSH, addressing issues of dependency pollution and state chaos that arise from performing builds, tests, and long-running services directly in the host environment. This plugin exposes `mcp__sprites__*` tools via the MCP mechanism, supporting operations such as creating/listing Sprites, creating checkpoints, running test suites, starting web services, and obtaining URLs. It requires Node.js 20.19+ and DSH developer preview to run, and first-time use necessitates browser OAuth 2 via `mcp-remote`.