Interface DiscoverResult

Set when the source did not look at all, and why — a gated connector whose documents its host's robots.txt disallows, without --ignore-robots. Not an empty window either: a daily ka sync has to be able to tell "blocked" from "nothing new", and the run is not recorded as a sync.

Updated conditional-request state to persist.

True when the upstream reported nothing changed since the last run.

Set when the source was reached but could not be read — a search page whose markup contract broke, an API that answered in an unfamiliar shape.

It is deliberately not the same as refs: []. An empty window is an answer; this is the absence of one, and it is what tells FallbackSource that going somewhere else is warranted rather than a way of papering over a quiet month.

Non-fatal problems: a page that would not parse, a field that was missing.