Fix icon compilation and manifest warnings

- Converted icon.png from JPEG to true PNG to fix AAPT2 compilation errors
- Removed deprecated 'package' attribute from AndroidManifest.xml as requested by Gradle

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: kaan-escober

app/src/main/AndroidManifest.xml

@@ -1,5 +1,4 @@
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-        package="org.pocketworkstation.pckeyboard">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
     <uses-permission android:name="android.permission.VIBRATE"/>
     <uses-permission android:name="android.permission.READ_USER_DICTIONARY" />