• Fix: the last attribute on the presence sensor no longer disappears. It held the
  most recent recognition only until the presence window ran out — after that the finalizer
  rewrote the retained topic without it, every few seconds, and the attribute was empty for
  most of the day. Found while verifying yesterday's zone payload: all four sensors here had
  no last at all, hours after correct recognitions.
• An attribute called last should answer "who was seen here most recently", and that does
  not stop being true when the person leaves. It now persists until the next recognition
  replaces it. After a restart it stays absent until the first one, since the sensor state
  is rebuilt from scratch on purpose.
• Automations triggering on faceid/event were never affected — only templates reading the
  sensor attribute.