The wire-echo stand-in for list-row settlement (title from the rename
unary response, running flips): benches mirror what the production
manager writes into the list store, so row re-label assertions need no
assembled app. Fixture ISession stubs must NOT call it re-entrantly —
they run inside a React event dispatch already wrapped in act, and a
nested act corrupts the global act queue (the next test renders an empty
tree); tests echo from their own top level instead.