feat: Integrate dotenv for environment variable management and update .gitignore

lib/components/map/map_content.dart

@@ -4,6 +4,7 @@ import 'package:geolocator/geolocator.dart';
 import 'dart:convert';
 import 'package:http/http.dart' as http;
 import 'dart:ui' as ui;
+import 'package:flutter_dotenv/flutter_dotenv.dart';
 
 class MapContent extends StatefulWidget {
   const MapContent({super.key});
@@ -25,7 +26,7 @@ class _MapContentState extends State<MapContent> {
   
   List<PlaceSuggestion> _suggestions = [];
   
-  static const String _apiKey = 'AIzaSyBPxanjGyrWVjI4-hZmi086VdQFSEYT_2U';
+  static final String _apiKey = dotenv.env['GOOGLE_MAPS_API_KEY'] ?? '';
 
   @override
   void initState() {