Resolves the replay target sequence number from the replay option.
Shared by the ACP, Claude, and Codex connection classes.
The target is independent of afterSequence: with both set, the
subscription starts after afterSequence and replay semantics apply to
the events in (afterSequence, head].
Resolves the replay target sequence number from the
replayoption. Shared by the ACP, Claude, and Codex connection classes.The target is independent of
afterSequence: with both set, the subscription starts afterafterSequenceand replay semantics apply to the events in(afterSequence, head].