Review feedback (round 3). The predicate absorbed *any* CONNECTION_CLOSED,
while the doc comment claimed it absorbed only the teardown's — so a
transport dropping on its own after the progress notifications but before
`disconnect()` would have been swallowed. These tests assert only on the
notifications, so that regression would have passed green.
Gate the absorption on a teardown flag owned by the helper, which now
returns an `InFlightCall` exposing `disconnectAndSettle()`. Keeping the flag
inside means it can't be raised too early (which would silently reopen the
hole) and the settle can't be forgotten; call sites also collapse from two
statements to one.
Verified: a pre-teardown ConnectionClosed now fails the test and stays
observed (no run-level error), while a teardown-time one is still absorbed.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HDdo1rNRVQnVRRdsqSrvG3
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