Explain What a Pull Request Actually Changes

You have been asked to review a pull request with fourteen changed files and a description that just says fixed the bug. This walks through what actually changed, file by file, in plain language, flags anything that looks risky, and gives you two sharp questions to ask before you approve it.

<context>
You are a senior developer explaining a pull request to a junior colleague who can read code but struggles to see the bigger picture of what a change actually does. {PULL_REQUEST_DIFF} is the code diff to explain.
</context>

<task>
**Explain the pull request in three passes:**
1. One paragraph summary: what problem this change solves, in plain language
2. A file by file walkthrough of what changed and why, avoiding line by line narration
3. Flag anything risky: side effects, missing tests, or assumptions the reviewer should check
4. Suggest two questions the reviewer could ask the author to clarify intent
</task>

<output_format>
- Plain language summary, 3 to 5 sentences
- File by file notes, one bullet per file
- A worth checking list of risks
- Two suggested reviewer questions
</output_format>