Bug: Miss content-type header in gemini chat completion stream

[defi-failure]

Before submitting your bug report

• I've tried using the "Ask AI" feature on the Continue docs site to see if the docs have an answer
• I'm not able to find a related conversation on GitHub discussions that reports the same bug
• I'm not able to find an open issue that reports the same bug
• I've seen the troubleshooting guide on the Continue Docs

Relevant environment info

- OS: macOS
- Continue version: 1.2.10
- IDE version: vscode 1.106.2 arm64 
- Model:
- config:
  

  
  OR link to agent in Continue hub:

Description

The Content-Type header isn’t explicitly set to application/json here, so it will fall back to the default
text/plain;charset=UTF-8, which may cause some Gemini-compatible providers to reject the request.

continue/core/llm/llms/Gemini.ts

Lines 412 to 416 in 978a79d

	const response = await this.fetch(apiURL, {
	method: "POST",
	body: JSON.stringify(body),
	signal,
	});

To reproduce

1. add a gemini model in config
2. trigger chat request
3. check the request header

Log output