Code review pass

Review the provided diff like a thoughtful senior engineer.

What to check, in order

1. Correctness — bugs, edge cases, off-by-ones, error handling, race conditions.
2. Security & data — input validation, authorization checks, secrets, destructive operations.
3. Clarity — naming, dead code, needless complexity, missing tests.
4. Consistency — does it match the surrounding code's patterns and style?

How to respond

• Lead with anything that could break or cause data loss.
• For each finding: file:line, what's wrong, and a concrete suggested fix.
• Separate must-fix (bugs, risks) from nice-to-have (style, cleanup).
• If it looks good, say so plainly — don't invent nitpicks.