Follow-up to the live launch test: re-running gig-up while the rig was
already up would have opened a SECOND Ardour on the same session (an
'already open / locked' dialog) and a second Pulsar. Only SuperDirt was
guarded (skip if scsynth up).

Added ardour_up() (pgrep -f 'ardour-[0-9]', since the real binary is
ardour-9.2.0 behind the ardour9 wrapper script) and pulsar_up(), and gated
both launches on them. Now gig-up is a converge-to-ready button: run it at
any point and it starts only what's missing. Verified live with the full
rig up — SuperDirt/Ardour/Pulsar all correctly reported 'already running,
skipping', nothing duplicated. Serves #18 (dance with sound, not setup).