[Nevrdid]

Summary

• Add a native Linux x86-64 build workflow that publishes standalone binaries and a portable archive.
• Make runtime paths resolve relative to the executable, so the app can be launched directly from any working directory.
• Create data/games.db and its schema automatically on first launch; no pre-populated database or launcher script is required.
• Bundle only the TRIMUI Blue and TRIMUI Retro configuration, font, and UI image files used by the app; the build no longer checks out or downloads a theme repository.
• Include required app assets and ready-to-populate Roms/, Imgs/, and Emus/ directories.
• Resolve ROM artwork and emulator configuration from the portable library first while retaining TrimUI SD-card paths as fallbacks.
• Improve startup and runtime robustness for missing configuration, empty libraries, database/filesystem errors, and GUI initialization failures.
• Keep the interactive GUI launch and Add Game flow usable on desktop Linux without TrimUI system configuration.

Validation

• Manual x86-64 test: confirmed by the user on a clean setup; the binary launched and a game was added through the GUI.
• Native x86-64 CI: build, clean-first-launch database/schema smoke test, and portable-bundle smoke test passed on the previous revision.
• ARM64 CI: passed on the previous revision after updating the QEMU and Buildx actions.
• CI is rerunning against the latest minimal-assets change.

Out of scope

The Main Menu and the separate database-games / all-ROMs views will be implemented in a follow-up PR.

Commit history

The branch history has been consolidated into three topic-based commits: native build setup, runtime hardening, and portable desktop support. Related documentation is included with each topic.