Deploys that fail tell you why

A deploy could build fine and then never come up — and sit there saying “deploying” until you gave up on it. Now we diagnose it and say so: the container exited immediately, or it crashed on startup, or it never became ready, with the exit code and the last lines of its output.

We also stopped requiring you to know your start command. We detect it from your project, tell you what we detected, and if we genuinely cannot work it out, we say that plainly rather than guessing and failing strangely.