What:
- add a source-built qmd package and plugin metadata
- add a no-model-download qmd smoke check
- teach update-tools to notice qmd releases and the new sonoscli asset names
Why:
- nix-openclaw needs QMD as an internal runtime battery on Darwin and Linux
- the maintainer automation should not require a separate manual qmd bump path
Tests:
- nix build .#qmd .#checks.aarch64-darwin.qmd-smoke --accept-flake-config --no-link
- nix shell nixpkgs#go --command go test ./...
a0e7ac5ef1