fix: address remaining lint warnings

lib/data/services/overlay_service.dart

@@ -23,7 +23,7 @@ class OverlayService {
         () async {
           await FlutterOverlayWindow.showOverlay(
             enableDrag: true,
-            overlayTitle: "Speedometer",
+            overlayTitle: 'Speedometer',
             overlayContent: 'Speedo overlay active',
             flag: OverlayFlag.defaultFlag,
             visibility: NotificationVisibility.visibilityPublic,

pubspec.yaml

@@ -11,9 +11,6 @@ dependencies:
   flutter:
     sdk: flutter
   
-  # cupertino_icons: ^1.0.8
-  # Probably no icons needed for now
-  
   # GPS and Location Services - Essential only
   geolocator: ^14.0.2
   permission_handler: ^12.0.1
@@ -40,8 +37,8 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  flutter_lints: ^6.0.0
   flutter_launcher_icons: "^0.14.4"
+  flutter_lints: ^6.0.0
 
 flutter:
   uses-material-design: true