Watch task / dev console.

I almost always use a watch task to create a dedicated dev console that simply monitors for file changes and reruns unit tests. That way I always have lint and unit test results on the screen while I'm developing.

On save, the task should:
- lint
- run unit tests

Avoid any time-consuming activity. This should act like a realtime status monitor.

Locate the repository's watch-task configuration and identify the existing lint and unit-test entry points. Run those commands first; done means a watch task reruns lint and unit tests on save while avoiding time-consuming activity.

Written by the indexing model from the issue text.