static-test failed TestWriterBackoffGrowsAndResets and TestWriterLivestreamSubjects on CI's slower runner. The harness flushed by sending the session's tick twice, so a second flush was still running when flushed() returned. On a loaded machine it took in the words the test said next and published them before buffered() could see them, and buffered() waited out its 5 s. Delaying that flush by 20 ms and the test by 50 ms after each say reproduces both failures locally. flushed() now runs one flush of the session to completion and the tick never fires, so sessions flush only there and when they end. The test that needs the session's own flush stuck in the publisher keeps a tick of its own.