Add HTTPS configuration management system

- Add HTTPSConfig model for managing HTTPS settings
- Add admin routes for HTTPS configuration management
- Add beautiful admin template for HTTPS configuration
- Add database migration for https_config table
- Add CLI utility for HTTPS management
- Add setup script for automated configuration
- Add Caddy configuration generator and manager
- Add comprehensive documentation (3 guides)
- Add HTTPS Configuration card to admin dashboard
- Implement input validation and security features
- Add admin-only access control with audit trail
- Add real-time configuration preview
- Integrate with existing Caddy reverse proxy

Features:
- Enable/disable HTTPS from web interface
- Configure domain, hostname, IP address, port
- Automatic SSL certificate management via Let's Encrypt
- Real-time Caddyfile generation and reload
- Full audit trail with admin username and timestamps
- Support for HTTPS and HTTP fallback access points
- Beautiful, mobile-responsive UI

Modified files:
- app/models/__init__.py (added HTTPSConfig import)
- app/blueprints/admin.py (added HTTPS routes)
- app/templates/admin/admin.html (added HTTPS card)
- docker-compose.yml (added Caddyfile mount and admin port)

New files:
- app/models/https_config.py
- app/blueprints/https_config.html
- app/utils/caddy_manager.py
- https_manager.py
- setup_https.sh
- migrations/add_https_config_table.py
- migrations/add_email_to_https_config.py
- HTTPS_STATUS.txt
- Documentation files (3 markdown guides)

app/templates/base.html

@@ -376,7 +376,7 @@
     <header>
         <div class="container">
             <h1>
-                <img src="{{ url_for('static', filename='uploads/header_logo.png') }}" alt="DigiServer" style="height: 32px; width: auto;" onerror="this.src='{{ url_for('static', filename='icons/monitor.svg') }}'; this.style.filter='brightness(0) invert(1)'; this.style.width='28px'; this.style.height='28px';">
+                <img src="{{ url_for('static', filename='uploads/header_logo.png?v=1') }}" alt="DigiServer" style="height: 32px; width: auto; margin-right: 8px;" onerror="this.style.display='none';" onload="this.style.display='inline';">
                 DigiServer
             </h1>
             <nav>