* fix: session rename exits immediately due to focus race
Replace fragile onBlur handler with document mousedown listener for click-outside detection. Defer dropdown-initiated rename to onOpenChangeComplete (fires after CSS transition + cleanup). Use finalFocus instead of dead onCloseAutoFocus (never forwarded to Base UI).
* chore: remove dead editCancelledRef after onBlur removal
onBlur was replaced by document mousedown listener. editCancelledRef was only read in the old onBlur handler — its write in the Escape key handler was the sole remaining use.