Print when watch mode becomes idle

[JonnyBurger]

Goals

I use Turbo watch mode instead of tsc -w.

One thing I miss is TypeScripts message: Found 0 errors. Watching for file changes.
Currently there is no indication when all task are done.
On the last task, there is also no indication whether the task is still running or has completed.

This is important because I can only pick up work again when the compilation is done.

Non-goals

No response

Background

From this state it is not possible to tell whether compilation of the last task is done or still ongoing:

Other tools with "watch mode" always give some indication that the recompilation has succeeded: Next.js, tsc, Vite, Webpack etc.

Proposal

Print "Done." when watch tasks are done.