One failed send in use-terminal-live-input-commit aborts every keystroke
queued behind it, with the error swallowed by .catch(() => false). The
existing test resolves(true) on every send, so the failure branch was
uncovered.
Four arms: the abort itself, an ordinary negative on the healthy path, a
throwing sender, and a liveness control proving the queue recovers once
the chain settles. Deleting the abort takes 4 passed to 3 failed, with the
ordinary negative correctly surviving.
Scope is stated in the docblock: this is a transport send-queue abort,
reachable only via a real disconnect or RPC error. REQUEST_TIMEOUT_MS is
30s, so latency alone cannot reach the branch — consistent with #7094's
symptom class, not proven to be its cause.