deepseek-ai/DeepSeek-Coder-V2 ? reverse-engineered prompt

Build me a simple local demo for DeepSeek Coder V2 that lets me chat with the model and use it for coding help.

I want a clean interface where I can paste code, ask it to explain or fix bugs, and get a helpful answer back. It should be set up so I can switch between the Lite and full versions if needed, and it should work with long inputs because this model supports very large context. Please include clear setup steps, a way to point it at the Hugging Face model, and sensible defaults for coding tasks. If anything about running the model locally depends on current docs, look that up online and use the recommended approach.