Agents who refresh or dismiss the floating widget can now click a Join /
Rejoin action on the voice_call bubble to (re)connect to a ringing or
in-progress call. The CTA respects the same visibility rules as the
floating widget — outbound calls only surface for the initiator, and
inbound assigned calls only surface for the assignee.
useCallSession gains a manageSessionState option so the bubble can reuse
joinCall/activeCall without registering duplicate Twilio listeners or
running its own duration timer.
Closes PLA-117