release: v3.20.0 - Multi-Agent Code Review Automation

Integration of production-grade PR review patterns from Pat Cullen + Méthode Aristote.

New Features:
- Resource evaluation: Pat Cullen Final Review (5/5 - Critical)
- Enhanced /review-pr: +150 lines with Advanced Multi-Agent Review section
- Enhanced code-reviewer agent: +219 lines with anti-hallucination rules
- New workflow: Review Auto-Correction Loop in iterative-refinement.md
- Production example: Multi-Agent Code Review in ultimate-guide.md
- Reference updates: +3 entries (review_pr_advanced, review_anti_hallucination, review_auto_fix_loop)

Key Patterns:
- 3 specialized agents: Consistency, SOLID, Defensive Code Auditor
- Pre-flight check: git log Co-Authored-By detection
- Anti-hallucination: Grep/Glob verification before suggestions
- Severity classification: 🔴 Must Fix / 🟡 Should Fix / 🟢 Can Skip
- Convergence loop: review → fix → re-review (max 3 iterations)
- Conditional context loading: stack-agnostic decision table

Design Principles:
- Enrich existing files (no fragmentation)
- No breaking changes (review-pr.md template simple preserved)
- Complete attribution (Pat Cullen + Méthode Aristote with links)
- Audience-aware (beginner → advanced progression)

Files Modified:
- CHANGELOG.md, VERSION: bumped to 3.20.0
- docs/resource-evaluations/017-pat-cullen-final-review.md: NEW (120 lines)
- examples/commands/review-pr.md: 80 → 230 lines (+150)
- examples/agents/code-reviewer.md: 72 → 291 lines (+219)
- guide/workflows/iterative-refinement.md: 389 → 522 lines (+133)
- guide/ultimate-guide.md: +28 lines (Production Example section)
- machine-readable/reference.yaml: +3 entries
- README.md, guide/cheatsheet.md: version sync

Total: +537 insertions, 0 deletions (no breaking changes)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

machine-readable/reference.yaml

@@ -3,7 +3,7 @@
 # Source: guide/ultimate-guide.md
 # Purpose: Condensed index for LLMs to quickly answer user questions about Claude Code
 
-version: "3.19.0"
+version: "3.20.0"
 updated: "2026-01-30"
 
 # ════════════════════════════════════════════════════════════════
@@ -22,6 +22,10 @@ deep_dive:
   # Claude Code Releases
   claude_code_releases: "guide/claude-code-releases.md"
   claude_code_releases_yaml: "machine-readable/claude-code-releases.yaml"
+  # Code Review Automation (Pat Cullen, Jan 2026)
+  review_pr_advanced: "examples/commands/review-pr.md:81"
+  review_anti_hallucination: "examples/agents/code-reviewer.md:75"
+  review_auto_fix_loop: "guide/workflows/iterative-refinement.md:347"
   # Known Issues & Critical Bugs (verified community reports)
   known_issues: "guide/known-issues.md"
   known_issues_github_bug: "guide/known-issues.md:16"  # GitHub auto-creation bug
@@ -822,7 +826,7 @@ ecosystem:
       - "Cross-links modified → Update all 4 repos"
     history:
       - date: "2026-01-20"
-        event: "Code Landing sync v3.19.0, 66 templates, cross-links"
+        event: "Code Landing sync v3.20.0, 66 templates, cross-links"
         commit: "5b5ce62"
       - date: "2026-01-20"
         event: "Cowork Landing fix (paths, README, UI badges)"