Every active symptom definition enters pattern discovery as an outcome
channel SYMPTOM:<id>, labelled with its decrypted name (the data label
the interpretation already prefers over the key). The daily value is the
day's highest intensity in the person's zone; days without an occurrence
count as 0 only between the first and the last logged day. At most eight,
the active-definition cap. The SYMPTOM: prefix resolves to the illness
module in the surface map, so the family leaves the matrix with the
module, and the discovery guard lists the new fetcher.
