Refactor main application entry and enhance UI with file browser integration

- Changed application entry point to use QApplication for better compatibility with widgets.
- Set up QML UI style to support custom button backgrounds.
- Introduced LocalSettingsModel and FileBrowser for managing application settings and file selection.
- Updated QML components to reflect new data models and improve layout consistency.
- Enhanced Theme.qml with detailed comments and improved color management for better readability.

ISC/Tabs/SettingsTab.qml

@@ -419,7 +419,9 @@ Item {
                 opacity: (settingsScroll.ScrollBar.vertical.position <= 0 && settingsScroll.contentHeight > settingsScroll.height) ? (scrollHintTimer.running ? 1 : 0) : 0
 
                 Behavior on opacity {
-                    NumberAnimation { duration: 400 }
+                    NumberAnimation {
+                        duration: 400
+                    }
                 }
             }
         }
@@ -432,5 +434,4 @@ Item {
         repeat: false
         onTriggered: scrollHint.visible = false
     }
-
 }