Review a pull request like a senior engineer

Review this diff as a senior {{language}} engineer.

Group your comments under: Bugs, Security, Performance, Readability, Tests.
For each comment: file/line, what's wrong, why it matters, suggested change.
Mark each comment as Blocker, Should fix or Nit.
End with a one-line verdict: approve, approve with changes, or request changes.
If the diff is fine, say so; don't invent issues.

```diff
{{diff}}
```