Prepare for App Store submission

- Added public domain headers to all test files
- Updated Info.plist with required App Store keys:
  - ITSAppUsesNonExemptEncryption = NO
  - LSApplicationCategoryType = Social Networking
  - UIRequiresFullScreen = YES
- Created proper Assets.xcassets structure
- Configured AppIcon.appiconset with all icon references
- Removed last TODO comment
- Created comprehensive App Store submission checklist
- Updated project.yml to include Assets.xcassets

The app is now ready for App Store submission. All debug code has been removed,
icons are configured, and privacy/security compliance is documented.

bitchat/Services/NotificationService.swift

@@ -16,7 +16,7 @@ class NotificationService {
             if granted {
                 // Permission granted
             } else if let error = error {
-                print("[NOTIFICATIONS] Permission error: \(error)")
+                // print("[NOTIFICATIONS] Permission error: \(error)")
             }
         }
     }
@@ -51,7 +51,7 @@ class NotificationService {
         
         UNUserNotificationCenter.current().add(request) { error in
             if let error = error {
-                print("[NOTIFICATIONS] Error sending notification: \(error)")
+                // print("[NOTIFICATIONS] Error sending notification: \(error)")
             } else {
                 // Notification sent
             }