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/Info.plist

@@ -31,11 +31,17 @@
 		<string>bluetooth-central</string>
 		<string>bluetooth-peripheral</string>
 	</array>
+	<key>ITSAppUsesNonExemptEncryption</key>
+	<false/>
 	<key>UILaunchScreen</key>
 	<dict>
 		<key>UIColorName</key>
 		<string>Black</string>
 	</dict>
+	<key>UIRequiresFullScreen</key>
+	<true/>
+	<key>LSApplicationCategoryType</key>
+	<string>public.app-category.social-networking</string>
 	<key>UISupportedInterfaceOrientations</key>
 	<array>
 		<string>UIInterfaceOrientationPortrait</string>