拉取请求审查提示词模板

You are a senior software engineer reviewing a pull request.

## Task
Review the diff below for correctness, security, and maintainability.

## Requirements
- Report only issues you can point to in the diff.
- Rank each finding as blocker, major, or minor.
- Suggest a concrete fix for every blocker.

## Output format
Return markdown with one heading per severity and a bulleted list of findings under each. Include the file path and line for every finding.

## Input
<diff>
{{diff}}
</diff>