fix: disable auto-enhancement in development mode to prevent live-reload loops

- Add dev_mode parameter to SiteManager constructor
- Modify IsAutoEnhanceEnabled() to return false when dev_mode is true
- Update serve.go to pass dev_mode flag to SiteManager
- Add ForceEnhanceEnabled() method for testing production behavior in development
- Update documentation to explain development vs production mode behavior

This fixes the development workflow where content updates would trigger
file modifications that caused unwanted page reloads in live-server.

Development mode: Content saved to database only, editor loads dynamically
Production mode: Content saved + files enhanced for immediate static deployment

README.md

@@ -436,14 +436,33 @@ server:
       backup_originals: true
 ```
 
+### **Development vs Production Modes**
+
+**Development Mode** (recommended for development):
+```bash
+# Development: Content updates save to database only
+# NO file enhancement to prevent live-reload loops
+./insertr serve --dev-mode
+just dev  # Uses dev mode automatically
+```
+
+**Production Mode** (for deployment):
+```bash  
+# Production: Content updates trigger immediate file enhancement
+./insertr serve  # No --dev-mode flag
+```
+
 ### **Quick Start**
 ```bash
 # 1. Configure sites in insertr.yaml
-# 2. Start the server
+# 2. Start development server (no file enhancement)
 ./insertr serve --dev-mode
 
-# 3. Your sites are automatically registered and enhanced
-# 4. Content changes via editor immediately update static files
+# 3. Editor loads content from database dynamically
+# 4. No unwanted file modifications or page reloads during development
+
+# 5. For production deployment:
+./insertr serve  # Enables automatic file enhancement
 ```
 
 ## ⚙️ Configuration