Missing User-Agent header causes Cloudflare 403 on API requests

[SAKURAAUA]

Problem

API requests from OpenAICompatibleProvider are blocked by Cloudflare-protected endpoints (e.g. OpenCode Go) with HTTP 403, error code 1010.

Root Cause

The _request_headers() method in echobot/providers/openai_compatible.py:380 does not include a User-Agent header. Cloudflare interprets the request as coming from an automated bot and blocks it.

Steps to Reproduce

1. Configure .env with a valid API key targeting any Cloudflare-protected OpenAI-compatible endpoint
2. Start the bot
3. Any LLM request fails with 401/403

Suggested Fix

Add a User-Agent header to the request headers:

def _request_headers(self) -> dict[str, str]:
    return {
        "Authorization": f"Bearer {self.settings.api_key}",
        "Content-Type": "application/json; charset=utf-8",
        "User-Agent": "EchoBot/1.0",
        **self.settings.extra_headers,
    }

This allows the request to pass Cloudflare's browser integrity check.

[KdaiP]

已修复，测试在opencode go可以使用了