Complete the tui-02 spec acceptance criteria: delete the orphan
`connectSession`, `disconnectSession`, `sessionStreamJob`, and
`sessionWsSession` members from TuiWsClient, and remove the `send()`
fallback that previously routed ApprovalResponse over a per-session
socket. All ClientMessage types now travel the single global socket.
Server side: GlobalStreamHandler.handleClientMessage now actually
handles ApprovalResponse (was returning a protocol error), converting
to a domain ApprovalDecision and dispatching to the orchestrator —
mirrors SessionStreamHandler's prior logic.
Adds ApprovalResponseGlobalSocketRoundTripTest covering APPROVE and
STEER encode/decode through ProtocolSerializer.
kami
c8a599c64f