Add in-game settings menu with web panel sync

Features:
- SettingsActivity accessible via Menu button (keycode 82)
- Configure server URL and mode (online/offline) in-game
- Test connection before saving settings
- Switch to offline mode with one tap
- Sync settings from web admin panel
- Real-time status messages with emoji indicators

Implementation:
- Created 13 SettingsActivity Smali files (main + inner classes)
- Created activity_settings.xml UI layout
- Added SettingsActivity to AndroidManifest.xml (portrait mode)
- Modified MainActivity.smali to handle Menu button press
- Integrated with existing ServerManager for Nimble SDK overrides
- Settings stored in SharedPreferences (rr3_server_config.xml)

APK:
- Built and signed: RR3-v14-Settings-Menu.apk (103 MB)
- Keystore: rr3-release.keystore (alias: rr3key)
- Ready for distribution

Related server changes:
- ServerSettingsController.cs with 3 API endpoints
- DeviceSettings.cshtml admin page
- UserSettings database model and migration

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

smali_classes2/com/firemint/realracing/MainActivity.smali

@@ -2808,9 +2808,34 @@
 .end method
 
 .method public onKeyDown(ILandroid/view/KeyEvent;)Z
-    .locals 1
+    .locals 3
 
     .line 1518
+    # Check if Menu button (keycode 82) pressed
+    const/16 v0, 0x52
+
+    if-ne p1, v0, :cond_settings_check_done
+
+    # Open SettingsActivity
+    const-string v0, "RR3-Community"
+
+    const-string v1, "\u2699\ufe0f Menu button pressed - Opening Settings"
+
+    invoke-static {v0, v1}, Landroid/util/Log;->d(Ljava/lang/String;Ljava/lang/String;)I
+
+    new-instance v0, Landroid/content/Intent;
+
+    const-class v1, Lcom/firemint/realracing/SettingsActivity;
+
+    invoke-direct {v0, p0, v1}, Landroid/content/Intent;-><init>(Landroid/content/Context;Ljava/lang/Class;)V
+
+    invoke-virtual {p0, v0}, Lcom/firemint/realracing/MainActivity;->startActivity(Landroid/content/Intent;)V
+
+    const/4 p1, 0x1
+
+    return p1
+
+    :cond_settings_check_done
     invoke-virtual {p0, p1, p2}, Lcom/firemint/realracing/MainActivity;->handleKeyEvent(ILandroid/view/KeyEvent;)Z
 
     move-result v0