`merge_facts_into_device` applied one `replace_lists` flag to properties
and services alike, taking each wholesale from `facts`. But a PATCH only
carries the keys the client sent, so `{"properties": [...]}` replaced
services with `[]` — losing them for every canvas drawing the device and
stopping the scheduler from service-checking it. Symmetric the other way.
Gate the replace per list: a list absent from `facts` falls through to the
merge, which is a no-op against `None`. An explicit `[]` still clears, and
the canvas save path is unchanged since it always sends both keys.
ha-relevant: no
Pouzor
b0ad4688ec