Implement complete GPS speedometer functionality

Features implemented:
- Real-time GPS speed tracking with permission handling
- Customizable speed units (km/h, mph) with persistent settings
- Digital and analog speedometer display styles
- Dark/light theme support with system integration
- Optional metrics: coordinates, distance, trip time, GPS accuracy
- Trip reset functionality and error handling
- Modular architecture with Provider state management

Technical details:
- Added dependencies: geolocator, permission_handler, provider, shared_preferences
- Configured Android location permissions (FINE_LOCATION, COARSE_LOCATION)
- Portrait orientation lock for mobile-first experience
- Extensible settings system for future customization options
- Clean separation of concerns: providers, screens, widgets

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

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

test/widget_test.dart

@@ -11,20 +11,11 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:gps_speedo/main.dart';
 
 void main() {
-  testWidgets('Counter increments smoke test', (WidgetTester tester) async {
+  testWidgets('GPS Speedometer app loads', (WidgetTester tester) async {
     // Build our app and trigger a frame.
-    await tester.pumpWidget(const MyApp());
+    await tester.pumpWidget(const SpeedometerApp());
 
-    // Verify that our counter starts at 0.
-    expect(find.text('0'), findsOneWidget);
-    expect(find.text('1'), findsNothing);
-
-    // Tap the '+' icon and trigger a frame.
-    await tester.tap(find.byIcon(Icons.add));
-    await tester.pump();
-
-    // Verify that our counter has incremented.
-    expect(find.text('0'), findsNothing);
-    expect(find.text('1'), findsOneWidget);
+    // Verify that the app loads with the title
+    expect(find.text('GPS Speedometer'), findsOneWidget);
   });
 }