Add dedicated POST /agents/{id}/replay endpoint that uses
addCommandWithReply to wait for the agent ACK (30s timeout).
Returns the actual replay result (status, message, data) instead
of just a delivery confirmation.
Frontend toast now reflects the agent's response: "Replay completed"
on success, agent error message on failure, timeout message if the
agent doesn't respond.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>