actions/checkout is a Node action and the rust:* container has no node,
so its post-step failed with 'node: not found'. Use node:20-bookworm
(node present for checkout) and install Rust via rustup, running build,
clippy, and test in one shell.
Push-to-deploy had no automated gate. This Forgejo Actions workflow
builds the workspace, runs clippy as an error gate, and runs the tests
on every push and PR. Adjust runs-on to match the runner's label.