feat: Add flexible port configuration for development

- Change default ports to 7510 (backend) and 7511 (frontend) to avoid conflicts
- Add PORT environment variable support for both services
- Create docker-compose.dev.yml for development without SSL/nginx
- Add development script (scripts/dev.sh) for easy local development
- Create comprehensive port configuration documentation
- Update docker-compose.yml to support dynamic port configuration
- Add frontend .env.example with development settings

This allows running the application on custom ports internally without SSL,
making it easier to integrate with existing infrastructure.

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

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

README.md

@@ -72,16 +72,22 @@ The setup script will:
 #### Development Mode
 
 ```bash
+# Option 1: Use the development script
+./scripts/dev.sh
+
+# Option 2: Manual start
 # Terminal 1 - Backend
 cd backend
-npm run dev
+PORT=7510 npm run dev
 
-# Terminal 2 - Frontend
+# Terminal 2 - Frontend  
 cd frontend
-npm start
+PORT=7511 npm start
 ```
 
-Access at: http://localhost:3000
+Access at: 
+- Frontend: http://localhost:7511
+- Backend API: http://localhost:7510
 
 #### Production Mode (Docker)
 
@@ -90,12 +96,20 @@ Access at: http://localhost:3000
 # Select option 1 for quick deployment
 ```
 
-Access at: http://localhost
+Access at: http://localhost:7511 (or configured port)
 
 ## Configuration
 
 All configuration is managed through the `.env` file:
 
+### Port Configuration
+
+Default ports:
+- Backend API: 7510
+- Frontend UI: 7511
+
+To use different ports, see [Port Configuration Guide](docs/PORT_CONFIGURATION.md).
+
 ### Essential Settings
 
 ```env