feat(protocol): add session termination controls

control.go

@@ -26,6 +26,8 @@ const (
 	CtrlEntitlementViolation ControlType = "entitlement_violation"
 	CtrlPushNotify           ControlType = "push_notify"
 	CtrlPushNotifyResult     ControlType = "push_notify_result"
+	CtrlTerminateSession     ControlType = "terminate_session"
+	CtrlTerminateSessionAck  ControlType = "terminate_session_ack"
 )
 
 // ControlMessage is the wire format for relay control protocol messages.
@@ -99,6 +101,23 @@ type DeactivateDeveloperPayload struct {
 	DeveloperID string `json:"developer_id"`
 }
 
+// TerminateSessionPayload is sent by the relay to a daemon when an operator
+// terminates a single relay session from the dashboard. Unlike developer
+// deactivation, this is scoped to one relay session and should stop reconnects
+// for that relay session identity.
+type TerminateSessionPayload struct {
+	SessionID string `json:"session_id"`
+	Reason    string `json:"reason,omitempty"`
+}
+
+// TerminateSessionAckPayload is sent by the daemon after it has accepted a
+// terminate_session control message. The relay treats it as observability; the
+// durable termination tombstone is the reconnect-blocking authority.
+type TerminateSessionAckPayload struct {
+	SessionID string `json:"session_id"`
+	Stopped   int    `json:"stopped,omitempty"`
+}
+
 // ClientConnectedPayload is sent by the relay to the daemon when a PWA client
 // connects or reconnects. The daemon uses this to replay message history.
 type ClientConnectedPayload struct {

protocol_test.go

@@ -343,6 +343,12 @@ func TestDeactivateDeveloperPayloadRoundtrip(t *testing.T) {
 	assertRoundtrip(t, protocol.DeactivateDeveloperPayload{DeveloperID: "dev-1"})
 }
 
+func TestTerminateSessionPayloadRoundtrip(t *testing.T) {
+	t.Parallel()
+	assertRoundtrip(t, protocol.TerminateSessionPayload{SessionID: "relay-1", Reason: "operator"})
+	assertRoundtrip(t, protocol.TerminateSessionAckPayload{SessionID: "relay-1", Stopped: 2})
+}
+
 func TestClientConnectedPayloadRoundtrip(t *testing.T) {
 	t.Parallel()
 	assertRoundtrip(t, protocol.ClientConnectedPayload{SessionID: "sess-123"})
@@ -557,6 +563,8 @@ func TestControlTypeConstants(t *testing.T) {
 		protocol.CtrlEntitlementViolation: "entitlement_violation",
 		protocol.CtrlPushNotify:           "push_notify",
 		protocol.CtrlPushNotifyResult:     "push_notify_result",
+		protocol.CtrlTerminateSession:     "terminate_session",
+		protocol.CtrlTerminateSessionAck:  "terminate_session_ack",
 	}
 	for ct, want := range expected {
 		if string(ct) != want {