a bunch of flutter updates

walkguide-mobile/walkguide_app/lib/core/constants/app_constants.dart

@@ -2,6 +2,7 @@ import 'package:shared_preferences/shared_preferences.dart';
 
 class AppConstants {
   static const String _serverUrlKey = 'server_base_url';
+  static const String _selectedYoloModelKey = 'selected_yolo_model';
 
   // Ambil base URL dari SharedPreferences
   static Future<String?> getServerUrl() async {
@@ -12,18 +13,29 @@ class AppConstants {
   // Simpan URL setelah berhasil connect
   static Future<void> setServerUrl(String url) async {
     final prefs = await SharedPreferences.getInstance();
-    // Trim trailing slash
-    final cleaned = url.endsWith('/') ? url.substring(0, url.length - 1) : url;
+    final cleaned = normalizeServerUrl(url);
     await prefs.setString(_serverUrlKey, cleaned);
   }
 
+  static String normalizeServerUrl(String url) {
+    var cleaned = url.trim();
+    if (!cleaned.startsWith('http://') && !cleaned.startsWith('https://')) {
+      cleaned = 'http://$cleaned';
+    }
+    while (cleaned.endsWith('/')) {
+      cleaned = cleaned.substring(0, cleaned.length - 1);
+    }
+    return cleaned;
+  }
+
   static Future<void> clearServerUrl() async {
     final prefs = await SharedPreferences.getInstance();
     await prefs.remove(_serverUrlKey);
   }
 
   static String buildApiUrl(String baseUrl) => '$baseUrl/api/v1';
-  static String buildWsUrl(String baseUrl) => baseUrl.replaceFirst('http', 'ws') + '/ws';
+  static String buildWsUrl(String baseUrl) =>
+      '${baseUrl.replaceFirst('http', 'ws')}/ws';
 
   // Timeouts
   static const Duration connectTimeout = Duration(seconds: 10);
@@ -39,6 +51,16 @@ class AppConstants {
   static const String yoloLabelsPath = 'assets/models/labels.txt';
   static const int yoloInputSize = 640;
 
+  static Future<String> getSelectedYoloModelPath() async {
+    final prefs = await SharedPreferences.getInstance();
+    return prefs.getString(_selectedYoloModelKey) ?? yoloModelPath;
+  }
+
+  static Future<void> setSelectedYoloModelPath(String path) async {
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setString(_selectedYoloModelKey, path);
+  }
+
   // Agora - ganti dengan App ID dari agora.io
   static const String agoraAppId = 'YOUR_AGORA_APP_ID';
-}
+}