The first version told a cold reader to wait for the peer session to commit
tools/check-mix.py and tools/gig-log.py before the main tree could be
fast-forwarded. That precondition does not exist, and left as written it would
have parked the tree waiting on a commit that was never coming.

The peer flagged it; verified independently before amending. For both files the
working-tree blob equals origin/master and equals f56775ae, and only HEAD differs.
They show as 'M' because the shared tree's HEAD (5468507b) predates master's
shared-ladder refactor (27f23515, which changed both to import
tools/ardour_session.py) — the tree already holds the post-refactor content. Not
in-flight work: the tree is simply behind its own HEAD's successor.

Also verified, since 'one command' is a promise: HEAD is a true ancestor of
f56775ae, and the branch touches NONE of PLN's five modified .tidal files, so his
set prep survives the fast-forward untouched.

The caution that remains is a different one, and it is real: the live rig runs
from that tree via ~/.local/bin symlinks, so the fast-forward swaps code under a
running system and wants three units restarted afterwards. That is PLN's call
with eyes on the rig, not a housekeeping step to slip in overnight.