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/validate-prompt.sh

@@ -0,0 +1,43 @@
+#!/bin/bash
+# Validate user prompts
+# Hook: UserPromptSubmit
+
+# Read prompt from stdin
+PROMPT=$(cat)
+
+echo "🔍 Validating prompt..."
+
+# Check for dangerous operations
+DANGEROUS_PATTERNS=(
+  "rm -rf /"
+  "delete database"
+  "drop database"
+  "format disk"
+  "dd if="
+)
+
+for pattern in "${DANGEROUS_PATTERNS[@]}"; do
+  if echo "$PROMPT" | grep -qi "$pattern"; then
+    echo "❌ Blocked: Dangerous operation detected: $pattern"
+    exit 1
+  fi
+done
+
+# Check for production deployments
+if echo "$PROMPT" | grep -qiE "(deploy|push).*production"; then
+  if [ ! -f ".deployment-approved" ]; then
+    echo "❌ Blocked: Production deployment requires approval"
+    echo "Create .deployment-approved file to proceed"
+    exit 1
+  fi
+fi
+
+# Check for required context in certain operations
+if echo "$PROMPT" | grep -qi "refactor"; then
+  if [ ! -f "tests/" ] && [ ! -f "test/" ]; then
+    echo "⚠️  Warning: Refactoring without tests may be risky"
+  fi
+fi
+
+echo "✅ Prompt validation passed"
+exit 0