Introducing latest rolling pre-release builds from main

[noctonca]

We've added a rolling pre-release tag, latest, that's rebuilt from main on every push. It has the same artifact shape as tagged releases: Linux AppImage (x86_64, aarch64), Windows portable ZIP (x64), and now macOS DMG (arm64). It just always tracks the tip of the tree.

Why we did this

Between tagged releases like v0.9.0 there's a lot of motion on main: crash fixes, platform polish, new debug console commands, gamepad tweaks. Until now, getting any of that meant either waiting for the next tag or building from source, which is a real ask for play testers and folks running the engine on handhelds. The rolling tag closes that gap. If a fix landed an hour ago, it's downloadable an hour ago.

It's also a forcing function for our CI. Every push has to produce shippable artifacts on three OSes and two Linux architectures, which keeps the cross-platform story honest. If a platform's build leg fails, only that one artifact is missing. The others still update, and previous rolling builds remain accessible through the commit history.

When to use which

• Tagged releases (v0.9.0, etc.): what you want if you're playing through the game, sharing builds with friends, or filing bugs you want us to take seriously. Play tested, changelog documented, stable.
• latest rolling pre-release: what you want if you're chasing a specific recent fix, helping us shake out a platform issue, or just curious. May contain in-progress changes that haven't been play tested.

Bug reports from latest are very welcome. Please include the commit hash from the release page so we know exactly what you ran.

The PR behind this is #108.

Try it out: https://github.com/LBALab/lba2-classic-community/releases/tag/latest