Stray .old/.orig/.new developer backups (com_showroom uploadgroup,
jckman restorers/toolbar, maintenance2 tips.php) do not belong in a
clean baseline source — they are not deployed code and would only add
noise to the baseline. Remove them at the source rather than filtering
them in build-baseline.sh (the source is the right place to fix this).
The cadline/backend/maintenance SUBMODULE (maintenance.git) also holds
a tips.php.orig — that must be removed in the submodule repo separately.
Ref: cadline/infra#180
