Results 3 issues of shadowgate15

Whenever watch is running, anytime you change an asset file all assets files are rebundled. Might be nice if this only reloaded the file that was changed.

Currently if you do the following: ``` test('invalid name', async (t) => { await t.throwsAsync( sao.mock({ generator }, { ...defaults, name: 'Foo Bar Baz Beep' }), { message: /package name...

#### What problem are you trying to solve? Would be good to provide a `bree.modify` function to modify an existing job and rerun validation on the job.

enhancement