BoomerAng9/deepseek-harness ? reverse-engineered prompt

Build me a local agent harness called DeepSeek Harness that feels like a clean developer tool for running AI workflows from a web app.

I want it to launch a web UI on my machine, open in the browser by default, and let me run it from a source checkout after installing dependencies and building once. The main idea is that everything should be plugin based, so the core stays small and the features come from plugins that can be added or swapped out easily.

Please make it feel polished enough for a real open source project, with a simple startup flow, helpful docs, and clear separation between the core app, plugins, and the web interface. If you need to check current docs or patterns for anything, look them up online. Also make sure it works well for local development and is organized so it can keep evolving without breaking the whole app every time a plugin changes.