This is impressive work llama! I'll need a bit more time to review the current code properly, but I wanted to give you some quick feedback to unblock you.

• Happy with the general direction, and don't think we'll want to keep around the terminal-based approach with this in place, subject to the next point. Given that, it might be nice if the code for this lived in qt/launcher, as that'll also make it easier to track any changes made to the old launcher code.
• We'll probably want to get an alpha build of this into the hands of testers as soon as basic functionality is working on all platforms, so we can identify any unanticipated compatibility issues that might prevent us from switching away from the terminal approach.
• Not urgent, but it would be nice if our build system eventually provides a target that takes care of installing the cli tool (like we do for cargo-nextest).
• Your pty approach saves us a bunch of work, and may end up being our best approach. Downside is that we won't be able to show overall progress to users who might be daunted by the per-package output. It might be worth starting a discussion with uv about possible alternatives, such as a flag that restricts progress to a single overall bar, or exposes progress events over a socket or the network. If they're amenable to something like that and we decide it's a good idea, we could send through a PR to make it easier for them to accept.
• I wasn't able to test the install process on a Mac, as I get the following during startup:

thread 'tokio-runtime-worker' panicked at qt/launcher-gui/src-tauri/src/commands.rs:140:58:
called Result::unwrap() on an Err value: Read "/Users/dae/Local/rust/Resources/.python-version"

The existing code expects the launcher binary to be run from within an app bundle. This is how the layout looks like for the terminal version:

$ ls -aR ../../../out/launcher/Anki.app
.        ..       Contents

../../../out/launcher/Anki.app/Contents:
.          ..         Info.plist MacOS      Resources

../../../out/launcher/Anki.app/Contents/MacOS:
.                 ..                install_name_tool launcher          uv

../../../out/launcher/Anki.app/Contents/Resources:
.               ..              .python-version Assets.car      pyproject.toml  versions.py

build.sh in qt/launcher/mac takes care of the building that folder after compiling. If you don't have access to a Mac, I can take care of this before the alpha test.

Should hopefully have more comments in the next few days!

I probably won't have a chance to circle back to this until late this week/early next week :-( If you're blocked on anything, please let me know and I'll try to get to that earlier.