Add a build flag on deploy

Currently, the `deploy` command assumes that the project has already been built or packaged.

We should either (or both):
- Add some safeguards to prevent deploying if the artifacts don't exist
- Add a `--build` flag to the `deploy` command similar to how we have on the `run` command.

Start by locating the deploy and run command entry points and comparing how the existing build behavior is handled. Check what happens when deploy artifacts are absent, then define completion around either preventing an invalid deployment, supporting a deploy-time build flag, or both, with corresponding command coverage.

Written by the indexing model from the issue text.