🐛 Fix PWA install prompt showing after installation

Fixed critical bug where PWA install message continued showing after app installation

- ✅ Enhanced PWA installation status detection
- ✅ Fixed install prompt logic to hide after installation
- ✅ Improved Service Worker update handling
- ✅ Added proper installation state management
- ✅ Enhanced iOS Safari PWA detection
- ✅ Added installation preferences storage

- Added installationChecked flag for better state management
- Enhanced checkInstallationStatus() method with multiple detection methods
- Improved shouldShowPrompt() logic to prevent showing after installation
- Added periodic installation monitoring for iOS devices
- Enhanced Service Worker activation event handling
- Added PWAUtils.checkInstallationStatus() utility method

- public/src/pwa/install-prompt.js (major refactor)
- public/index.html (PWA logic improvements)
- public/sw.js (Service Worker enhancements)

- PWA install message no longer shows after successful installation
- Only update notifications are shown for installed PWAs
- Proper distinction between install prompts and update notifications

Version: Enhanced Security Edition v4.01.413

SECURITY_DISCLAIMER.md

@@ -1,6 +1,6 @@
 # Security Disclaimer and Terms of Use
 
-## 🔒 SecureBit.chat Enhanced Security Edition v4.01.412
+## 🔒 SecureBit.chat Enhanced Security Edition v4.01.413
 
 ### Important Legal Notice
 
@@ -203,6 +203,6 @@ This software is created to:
 ---
 
 *Last Updated: 08.07.2025*  
-*Version: Enhanced Security Edition v4.01.412*
+*Version: Enhanced Security Edition v4.01.413*
 
 **USE AT YOUR OWN RISK AND RESPONSIBILITY**