feat(balatrobot): CLI support for Linux through Proton

[S1M0N38]

Description

Currently, BalatroBot lacks CLI support for Linux (Proton). This feature request is to implement platform support for users running Balatro through Proton on Linux.

Context

As noted in the contributing guide, we currently support:

• macOS: src/balatrobot/platforms/macos.py
• Windows: src/balatrobot/platforms/windows.py
• Linux (Native): src/balatrobot/platforms/native.py

Proposed Implementation

Create a new platform module at src/balatrobot/platforms/linux.py that handles:

• Detecting Proton installation and Balatro through Steam
• Launching Balatro with appropriate Proton runtime
• Managing the game process lifecycle
• Injecting the BalatroBot mod into the Proton prefix

References

Contributors can refer to the existing platform implementations for guidance on structure and required functionality.

Additional Information

This would enable Linux users running Balatro through Steam Play/Proton to use BalatroBot without requiring a native Linux build of the game.

[S1M0N38]

This issue was close by accident. I'm reopening. We still need to add the support for Linux through Proton.