feat request: add GLM Coding Plan as a LLM provider #134
Description
Add support for GLM Coding Plan (ChatGLM by Zhipu AI) as an LLM provider option.
Current state: Dexter supports OpenAI, Anthropic, Google Gemini, Ollama, and OpenRouter as LLM providers (configured in src/model/llm.ts via getChatModel() and resolveProvider()).
Proposed changes:
- Add a glm provider to resolveProvider() in src/model/llm.ts
- Add GLM model instantiation in getChatModel() (likely via the OpenAI-compatible API endpoint, since GLM offers an OpenAI-compatible interface)
- Register available GLM models (e.g., glm-4, glm-4-flash, codegeex-4) in the model selection flow
- Add GLM_API_KEY environment variable support
- Update env.example with the new key
Notes: GLM's API is OpenAI-compatible, so it may be possible to use ChatOpenAI with a custom baseURL pointing to https://open.bigmodel.cn/api/paas/v4/, similar to how OpenRouter is handled.