- Fix MCP test connection authentication issues by updating frontend
request format
- Add variables field with authorization_token for template substitution
- Change headers to use proper Authorization Bearer format with template
variable
🤖 Generated with [Claude Code](https://claude.ai/code)
### What problem does this PR solve?
correct MCP server authentication header format in frontend
### Type of change
* [x] Bug Fix (non-breaking change which fixes an issue)
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Co-authored-by: Marvion <marvionliu@wukongjx.cn>
Co-authored-by: Claude <noreply@anthropic.com>
