Codex CORE: the dismissed-set was keyed by bare approval_id, but gateway/run
sources preserve externally-supplied IDs without session namespacing — so two
sessions carrying the same approval_id collide and dismissing in session A hides
session B's still-pending approval. Fix: _approvalDismissKey(sid, approvalId)
builds a session-namespaced composite key, threaded through _isApprovalDismissed,
_markApprovalDismissed, _unmarkApprovalDismissed + all 5 call sites (showApprovalCard,
dismissApprovalCard, respondApproval, no-pending poll cleanup). Updated 4 stale
assertions to the namespaced signatures + added a functional node-driver
cross-session-collision regression (proven non-vacuous).
Co-authored-by: Rod Boev <rod.boev@gmail.com>