The sidebar had said ATTENTION · 1 since the first commit. It was reading a
fixture's needs_input flag that no live pane ever set, so the number was frozen
at whatever the demo data said.
Attention is now built from observed signals, and every signal carries an
AttentionSource. The rule, enforced by is_countable on the source rather than by
a filter at the call site: a guess may draw a row and sort it, but may not
increment the count. That is decision 0012's provenance rule applied to a
different claim, for the same reason — a wrong count teaches people to ignore
the number, and the number is the whole point of the section.
RuntimeObserved is the only source that produces signals today, from process
exits and runtime faults. The two ACP kinds are declared and never constructed,
so there is a shape for the ACP client to fill and nobody is tempted to
approximate "asked you a question" by watching output for a question mark.
RuntimeEvent::Exited carries a u32 code that was being formatted into a sentence
and discarded; AttentionKind::Finished keeps it, which is why a row can say
"Exited with code 42" instead of "needs attention".
Verified live: exiting a pane with code 42 produces ATTENTION · 1, a row reading
"Exited with code 42 · observed", a dimmed pane banner offering restart, and a
live-PTY count that drops from 3/3 to 2/3.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
