fix(engine): fix broken URL resolution in Ollama and MLX engines

[keith666666]

Summary

Both OllamaEngine and MLXEngine produce malformed URLs when making API requests, causing HTTP 405 errors.

Root cause — two bugs in URL construction:

1. axios.create({ url: ... }) was used instead of baseURL. In axios, url sets a default request URL, not a base prefix — so it gets ignored when .post(path, data) is called separately.

2. this.client.getUri(this.config) was used to resolve the POST URL, but the engine config contains non-axios properties (apiKey, model, maxTokensOutput, etc.) that pollute URL resolution. When apiKey is null (the default for Ollama), the URL resolves to http://localhost:11434/null, which returns HTTP 405.

Fix: Construct the full endpoint URL once in the constructor and pass it directly to axios.post() — matching how FlowiseEngine already works.

Before (broken)

this.client = axios.create({
  url: config.baseURL
    ? `${config.baseURL}/${config.apiKey}`  // → "http://localhost:11434/null"
    : 'http://localhost:11434/api/chat',
});

// getUri merges non-axios config properties → malformed URL
const response = await this.client.post(
  this.client.getUri(this.config), params
);

After (fixed)

this.chatUrl = `${config.baseURL || 'http://localhost:11434'}/api/chat`;
this.client = axios.create({ headers });

const response = await this.client.post(this.chatUrl, params);

Test plan

• npm test — all 37 unit tests pass
• npm run build — builds successfully
• Verified end-to-end with Ollama (qwen3.5:2b) — commit message generated successfully

[di-sukharev]

thank you @keith666666