Phase 1: Add LocalSaveManager for offline mode

- Created LocalSaveManager.smali with JSON save/load functionality
- Implements save file at /sdcard/Android/data/com.ea.games.r3_row/files/offline_save.json
- Added currency helper methods (getCurrency, setCurrency)
- Initialized in MainActivity.onCreate()
- Save structure includes: player, currency, dailyReward, cars, progress

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

smali_classes2/com/firemint/realracing/MainActivity.smali

@@ -2237,6 +2237,9 @@
     :cond_0
     invoke-static {p0}, Lcom/firemint/realracing/AppProxy;->SetActivity(Landroid/app/Activity;)V
 
+    # Initialize LocalSaveManager for offline mode
+    invoke-static {p0}, Lcom/firemint/realracing/LocalSaveManager;->initSaveFile(Landroid/content/Context;)V
+
     .line 353
     invoke-virtual {p0}, Landroid/app/Activity;->getApplication()Landroid/app/Application;