feat: Claude PR Reviewer agent — structured Markdown code reviews

[FraktalDeFiDAO]

🔍 Claude PR Reviewer Agent

What this does

A Claude Code sub-agent that takes a PR diff as input, analyzes it, and returns a structured Markdown review comment.

Acceptance Criteria Met

Requirement	Status
CLI: claude-review --pr https://github.com/owner/repo/pull/123	✅ Implemented
GitHub Action workflow YAML included	✅ .github/workflows/pr-review.yml
Structured Markdown: Summary (2-3 sentences)	✅
Structured Markdown: Identified risks (list)	✅
Structured Markdown: Improvement suggestions (list)	✅
Structured Markdown: Confidence score (Low/Medium/High)	✅
Tested on 2+ real GitHub PRs with outputs	✅ 3 PRs tested
README with setup and usage	✅

Architecture

src/
├── index.ts       # CLI entry point & arg parsing
├── types.ts       # TypeScript interfaces
├── github.ts      # GitHub API (fetch diff, post comments)
├── claude.ts      # Anthropic API (AI-powered review)
├── template.ts    # Template-based review (no API key)
└── formatter.ts   # Markdown output formatting

agents/
└── pr-reviewer.md # Claude Code sub-agent prompt

.github/workflows/
└── pr-review.yml  # GitHub Action workflow

Two Modes

1. AI Mode (with ANTHROPIC_API_KEY): Sends diff to Claude for deep analysis
2. Template Mode (no API key): Pattern detection + heuristic analysis

Usage

# Install
npm install && npm run build

# Basic review (template mode)
node dist/index.js --pr https://github.com/owner/repo/pull/123

# AI-powered review
export ANTHROPIC_API_KEY=sk-ant-...
node dist/index.js --pr https://github.com/owner/repo/pull/123

# Post review as PR comment
node dist/index.js --pr https://github.com/owner/repo/pull/123 --post

# Save to file
node dist/index.js --pr https://github.com/owner/repo/pull/123 --output review.md

Test Outputs

See test-outputs/ for real PR review samples:

• typescript-review.md — microsoft/TypeScript#63364
• deno-review.md — denoland/deno#33224
• nextjs-review.md — vercel/next.js#92576