Add C64GS Compatibility Support for Commodore 64 Games

📋 Summary

Add a way to identify Commodore 64 Games System compatible titles within the existing Commodore 64 platform.

❗ Problem

The Commodore 64 Games System was a keyboardless console variant of the Commodore 64.

Some Commodore 64 cartridge games were designed or adapted for joystick-only controls, making them suitable for C64GS-style setups.

Currently, users may need to track these games manually.

💡 Proposal

Add metadata, filtering, or playlist support for C64GS-compatible Commodore 64 games.

This could allow users to:

• Mark games as C64GS compatible

• Filter C64GS-ready cartridge games

• Create a dedicated C64GS playlist without duplicating database entries

• Store notes about joystick-only controls or required emulator settings

📦 Benefits

• Avoids duplicate Commodore 64 database entries

• Supports users who want C64GS-style collections

• Preserves the distinction without splitting the platform unnecessarily

• Improves organization for cartridge-focused Commodore 64 users

⚠️ Considerations

This should remain part of the Commodore 64 platform rather than becoming a separate Games Database platform, since the software library overlaps heavily with standard Commodore 64 cartridge releases.