`start_all()` was logging "starting {name}" before appending the
process to `self.procs`, so a SIGTERM arriving between the log write
and the append would call `request_shutdown()` with the new daemon
absent from `self.procs` and therefore never forwarded SIGTERM.
Moving the log after the append eliminates the window.
Signal handlers are also moved before `sup.start_all()` in `main()` so
they are registered before any child is spawned; previously there was a
window where SIGTERM used the default handler (silent process death) if
it arrived between `start_all()` returning and `signal.signal()`.
`TestMainEndToEnd._run` is updated to use a reader thread and a
`wait_for_output` synchronisation barrier instead of a fixed sleep, so
`test_sigterm_clean_shutdown` does not race against slow CI startup time.
didericis-claude
a245d8a392