refactor: Reorganize repository structure for optimal learning path

Reorder folders based on learning dependencies, complexity, and frequency of use:
- 01-slash-commands (unchanged) - Quick wins for beginners
- 02-memory (was 03) - Essential foundation
- 03-skills (was 05) - Auto-invoked capabilities
- 04-subagents (was 02) - Task delegation
- 05-mcp (was 04) - External integration
- 06-hooks (was 07) - Event automation
- 07-plugins (was 06) - Bundled solutions
- 08-checkpoints (unchanged) - Safe experimentation
- 09-advanced-features (unchanged) - Power user tools

Documentation improvements:
- Add LEARNING-ROADMAP.md with detailed milestones and exercises
- Simplify README.md for better scannability
- Consolidate Quick Start and Getting Started sections
- Combine Feature Comparison and Use Case Matrix tables
- Reorder README sections: Learning Path → Quick Reference → Getting Started
- Update all cross-references across module READMEs

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

07-plugins/pr-review/hooks/pre-review.js

@@ -0,0 +1,37 @@
+#!/usr/bin/env node
+
+/**
+ * Pre-review hook
+ * Runs before starting PR review to ensure prerequisites are met
+ */
+
+async function preReview() {
+  console.log('Running pre-review checks...');
+
+  // Check if git repository
+  const { execSync } = require('child_process');
+  try {
+    execSync('git rev-parse --git-dir', { stdio: 'pipe' });
+  } catch (error) {
+    console.error('❌ Not a git repository');
+    process.exit(1);
+  }
+
+  // Check for uncommitted changes
+  try {
+    const status = execSync('git status --porcelain', { encoding: 'utf-8' });
+    if (status.trim()) {
+      console.warn('⚠️  Warning: Uncommitted changes detected');
+    }
+  } catch (error) {
+    console.error('❌ Failed to check git status');
+    process.exit(1);
+  }
+
+  console.log('✅ Pre-review checks passed');
+}
+
+preReview().catch(error => {
+  console.error('Pre-review hook failed:', error);
+  process.exit(1);
+});