dev mode: log APP_MIDDLEWARE count

[chrisdickinson]

Use case: if a user accidentally removes the APP_MIDDLEWARE export without expecting to, we should give them a heads up. We could do this by always logging the total app-attached middleware count on startup in dev mode, and additionally grepping the file for APP_MIDDLEWARE if the count is zero and logging a big message with steps to remedy the situation.

[ceejbot]

I sort of want the boltzmann:routes run target to grow a bit and export middleware info, though maybe at that point it's not very routes-y and would need another name.

[chrisdickinson]

I sort of want the boltzmann:routes run target to grow a bit and export middleware info, though maybe at that point it's not very routes-y and would need another name.

This is valuable, & might be worth tracking as a separate issue!