Initial commit: Site Builder with PHP API backend

Visual drag-and-drop website builder using GrapesJS with:
- Multi-page editor with live preview
- File-based asset storage via PHP API (no localStorage base64)
- Template library, Docker support, and Playwright test suite

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

DOCKER.md

@@ -0,0 +1,71 @@
+# Site Builder - Docker Container
+
+## Quick Start
+
+**Start the container:**
+```bash
+cd /home/jknapp/code/site-builder
+docker-compose up -d
+```
+
+**Or use the management script:**
+```bash
+./docker-manage.sh start
+```
+
+**Access the site builder:**
+- From Windows: http://localhost:8081
+- From WSL: http://localhost:8081
+
+## Benefits
+
+- ✅ **Auto-restarts** - Container restarts automatically if it crashes
+- ✅ **Survives reboots** - Container auto-starts on system boot (unless stopped manually)
+- ✅ **Live updates** - Files are mounted, changes reflect immediately (no rebuild needed)
+- ✅ **Stable** - nginx is rock-solid, won't crash like Python server
+
+## Management
+
+**Using docker-manage.sh script:**
+```bash
+./docker-manage.sh start     # Start the container
+./docker-manage.sh stop      # Stop the container
+./docker-manage.sh restart   # Restart the container
+./docker-manage.sh logs      # View logs (Ctrl+C to exit)
+./docker-manage.sh status    # Check if running
+```
+
+**Using docker-compose directly:**
+```bash
+docker-compose up -d         # Start in background
+docker-compose down          # Stop and remove
+docker-compose restart       # Restart
+docker-compose logs -f       # View logs
+docker-compose ps            # Check status
+```
+
+## Technical Details
+
+- **Image:** nginx:alpine (lightweight, ~40MB)
+- **Port:** 8081 (host) → 80 (container)
+- **Volume:** Current directory mounted read-only to `/usr/share/nginx/html`
+- **Restart policy:** unless-stopped (auto-restarts on crash, survives reboots)
+
+## Troubleshooting
+
+**Container not starting?**
+```bash
+docker-compose logs
+```
+
+**Port already in use?**
+```bash
+sudo lsof -i :8081  # See what's using the port
+# Or change port in docker-compose.yml
+```
+
+**Rebuild if needed:**
+```bash
+docker-compose down
+docker-compose up -d --force-recreate
+```