Bare `entire scout` requires a profile selection (no silent default)

A bare invocation no longer auto-runs the default crew:

• interactive: a chooser lists profiles (pre-selecting the default) and the picked one runs;
• non-interactive: it prints the configured profiles and errors, so automation must name a profile (entire scout <name>) rather than silently spawning a default crew.

Explicit entire scout <name> and first-run setup are unchanged. Added a regression test; updated existing smoke/dispatch tests to name the profile explicitly.