v0.49.2

chore: add just commands for release workflow (#543)

Adds `just` and `gh` as Hermit dependencies and creates a justfile with
release commands:

- `just release` — auto-calculates next patch version, confirms, and
creates a GitHub release
- `just release-minor` — same but bumps the minor version
- `just release-status` — shows recent release workflow runs
- `just release-watch` — live-watches the latest release workflow
- `just release-list` — lists recent releases

Also updates RELEASE.md to reference the new commands.


ℹ️ The repo also has a Makefile - I've not touched that... perhaps we
eventually want to move it all to just 🤔 .

Co-authored-by: Amp <amp@ampcode.com>