Implement Native Proton Support and Per-Game Isolation for Linux.

[Pakrohk]

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Major Linux Backend Re-Architecture (Proton & XDG)

Hey team this PR is a big one It's not just a new feature it's a complete architectural rework for the Linux version of Hydra The goal is simple make Hydra a stable and first-class game launcher that can actually compete with Lutris and Steam on Linux.

I’ve focused on implementing proper standards isolation and execution logic.

Heads up: Since this is a core architectural change, please give the code a thorough review and feel free to refine the implementation (especially shell scripts) based on your deeper system understanding.

What I Implemented (The Technical Breakdown)

1. Standards and Filesystem Compliance (XDG)

• Necessity: Getting files out of the root user directory
• Execution: Strict adherence to the XDG Base Directory Specification to separate concerns:
  • Configuration files now live in $XDG_CONFIG_HOME/hydra
  • Persistent data (Prefixes Metadata) moves to $XDG_DATA_HOME/hydra
• Migration: Includes a fix for a critical bug in the data migration script to ensure zero user data loss when moving to the XDG structure

2. Proton Orchestration & Isolation Module

• True Isolation: Implemented logic to create and manage a dedicated, isolated WINEPREFIX for every single game This is stored in the $XDG_DATA_HOME/hydra/prefixes/{GameID} path and solves 99% of dependency conflicts
• Runner Discovery: Added a service to automatically find and list all available Proton and Wine runners on the system (checking standard Steam paths and custom folders)
• Launch Command: Refactored how games are executed We now use a wrapper script to correctly inject all necessary environment variables like STEAM_COMPAT_DATA_PATH and WINEPREFIX before starting the game binary

3. UI and Desktop Integration

• New Compatibility Tab: Added a dedicated UI section for Linux settings which gives the user full control
  • Runner Selection: Users can manually select the specific Proton/Wine version per game
  • Launch Options: Implemented management for launch arguments and environment variable toggles (e.g. for MangoHud Gamemode)
• Desktop Integration:
  • Steam Shortcuts: The system now generates Steam shortcuts that correctly point to the wrapper script ensuring the game launches seamlessly from Steam Deck/Big Picture Mode
  • .desktop Files: Generating and installing standard .desktop files so installed games appear directly in system application menus

⚠️ Focus Areas for Reviewers

1. Node.js Process Handling: Please verify the execution logic for spawning Proton processes (child_process) to ensure proper POSIX compliance and clean process termination
2. Wrapper Script: The shell wrapper script that sets the environment variables needs confirmation for maximum compatibility across different Linux distributions
3. Data Consistency: The updated data models and XDG migration logic need thorough testing against real-world user data to ensure stability

I haven't included screenshots because I believe a feature of this architectural depth is best reviewed by compiling and testing the code directly Thanks for taking the time to review

[sonarqubecloud]

Quality Gate passed

Issues
5 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[thegrannychaseroperation]

@Pakrohk thank you for your contribution. I'll be taking a look into it until weekend.
In the meantime, could you run Sonar on your code and check the issues? Thanks.

[moi952]

Hi,
This could be great, I have a few questions:

1- Does this mean the Proton version won't be available on Steam but only on Hydra, forcing us to return to the desktop?

2- Installing Windows redistributions doesn't seem to work for me (Bazzite). Do you plan to implement a button for installing the redistributions for each game? That would simplify things a lot.

Thanks for this development, I hope it will be merged quickly and that a new version of Hydra will be released :)