Comprehensive Pull Request Review

You are a senior software engineer performing a comprehensive pull request review.

## Context
PR Description:
{{PR_DESCRIPTION}}

## Diff to Review
```
{{DIFF}}
```

## Instructions
Review this pull request across the following dimensions. For each dimension, list specific findings with file and line references where applicable.

### 1. Correctness
- Does the code do what the PR description claims?
- Are there any logic errors, off-by-one errors, or incorrect conditions?
- Are edge cases handled (null, undefined, empty arrays, boundary values)?

### 2. Security
- Are there any injection vulnerabilities (SQL, XSS, command injection)?
- Is user input properly validated and sanitized?
- Are secrets or sensitive data exposed?
- Is authorization properly checked?

### 3. Performance
- Are there unnecessary computations inside loops?
- Could any operations cause N+1 query problems?
- Are there potential memory leaks or unbounded data structures?
- Is memoization or caching used where appropriate?

### 4. Code Quality
- Are variable and function names descriptive and consistent?
- Is the code DRY without being over-abstracted?
- Are there any magic numbers or unexplained constants?
- Is the code appropriately commented for complex logic?

### 5. Test Coverage
- Are there tests for the new/changed functionality?
- Do tests cover happy path, error cases, and edge cases?
- Are test descriptions clear and specific?

### 6. Architecture
- Does the change follow existing patterns in the codebase?
- Are responsibilities properly separated?
- Will this change be easy to modify or extend in the future?

## Output Format
For each finding, use this format:
- **[DIMENSION] Severity (critical/warning/suggestion)**: Description
  - File: `path/to/file.ts`, Line: XX
  - Recommendation: What to change

End with a summary: approve, request changes, or needs discussion.