Live proof: ecobee answers unicast mDNS with PTR only
(_hap._tcp.local -> "Main Floor._hap._tcp.local"), so the old
replace-on-probe wiped learned records every cycle. Merge by
(name, type) instead. CONFIG_PATH now env-overridable for tests.
Details: https://projects.knownelement.com/issues/619#note-5💘 Generated with Crush
Assisted-by: Crush:glm-5.2