88b12243

By: ananjiani <ananjiani@noreply.codeberg.org>

feat(aragorn): install uv system-wide (#339)

## Summary
Install `uv` on Aragorn as a system package (`environment.systemPackages`), not as a Hermes-only extra.

Hermes already has `/run/current-system/sw/bin` on PATH, so after Comin applies this it can run `uv` / `uvx` for ad-hoc Python tools (for example `youtube-transcript-api`). Desktop and Boromir already have `uv`; Aragorn did not.

## Deploy
Do not merge until you are happy with the review. After squash-merge to `main`, Comin on Aragorn should apply it. No extra Hermes config change is required.

## Test plan
- [ ] Review the one-file Nix diff
- [ ] After Comin: `command -v uv` as a normal user and from a Hermes tool shell
- [ ] `uv --version`

Co-authored-by: Ammar Nanjiani <ammar.nanjiani@gmail.com>
Reviewed-on: https://codeberg.org/ananjiani/infra/pulls/339