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>

06-hooks/security-scan.sh

@@ -0,0 +1,61 @@
+#!/bin/bash
+# Security scan on file write
+# Hook: PostToolUse:Write
+
+FILE=$1
+
+if [ -z "$FILE" ]; then
+  echo "Usage: $0 <file_path>"
+  exit 0
+fi
+
+echo "🔒 Running security scan on: $FILE"
+
+ISSUES_FOUND=0
+
+# Check for hardcoded passwords
+if grep -qE "(password|passwd|pwd)\s*=\s*['\"][^'\"]+['\"]" "$FILE"; then
+  echo "⚠️  WARNING: Potential hardcoded password detected in $FILE"
+  ISSUES_FOUND=1
+fi
+
+# Check for hardcoded API keys
+if grep -qE "(api[_-]?key|apikey|access[_-]?token)\s*=\s*['\"][^'\"]+['\"]" "$FILE"; then
+  echo "⚠️  WARNING: Potential hardcoded API key detected in $FILE"
+  ISSUES_FOUND=1
+fi
+
+# Check for hardcoded secrets
+if grep -qE "(secret|token)\s*=\s*['\"][^'\"]+['\"]" "$FILE"; then
+  echo "⚠️  WARNING: Potential hardcoded secret detected in $FILE"
+  ISSUES_FOUND=1
+fi
+
+# Check for private keys
+if grep -q "BEGIN.*PRIVATE KEY" "$FILE"; then
+  echo "⚠️  WARNING: Private key detected in $FILE"
+  ISSUES_FOUND=1
+fi
+
+# Check for AWS keys
+if grep -qE "AKIA[0-9A-Z]{16}" "$FILE"; then
+  echo "⚠️  WARNING: AWS access key detected in $FILE"
+  ISSUES_FOUND=1
+fi
+
+# Scan with semgrep if available
+if command -v semgrep &> /dev/null; then
+  semgrep --config=auto "$FILE" --quiet 2>/dev/null
+fi
+
+# Scan with trufflehog if available
+if command -v trufflehog &> /dev/null; then
+  trufflehog filesystem "$FILE" --only-verified --quiet 2>/dev/null
+fi
+
+if [ $ISSUES_FOUND -eq 0 ]; then
+  echo "✅ No security issues found"
+fi
+
+# Don't block the operation, just warn
+exit 0