fix: preserve assignment event revisions

server/api/service.go

@@ -58,6 +58,10 @@ type AssignmentView struct {
 	ProtocolVersion   int       `json:"protocol_version"`
 	Transport         string    `json:"transport"`
 	JoinAuthorisation string    `json:"join_authorisation"`
+	// Revision is routing metadata for the event stream, not part of the v1
+	// assignment response. Keeping it alongside the durable view prevents the
+	// REST recovery boundary from emitting a synthetic revision zero.
+	Revision uint64 `json:"-"`
 }
 
 type AssignmentProvider func(context.Context, string, string, time.Time) (AssignmentView, error)
@@ -509,10 +513,14 @@ func (s *Service) assignment(w http.ResponseWriter, r *http.Request) {
 		writeError(w, http.StatusServiceUnavailable, "assignment_unavailable")
 		return
 	}
-	_ = s.PublishControlPlaneEvent(ControlPlaneEvent{Event: "assignment_changed", Revision: 0, ResourceID: view.MatchID, OccurredAt: now, MatchID: view.MatchID, ServerID: view.ServerID, PlayerID: view.PlayerID})
+	_ = s.PublishControlPlaneEvent(assignmentChangedEvent(view, now))
 	writeJSON(w, http.StatusOK, view)
 }
 
+func assignmentChangedEvent(view AssignmentView, now time.Time) ControlPlaneEvent {
+	return ControlPlaneEvent{Event: "assignment_changed", Revision: view.Revision, ResourceID: view.MatchID, OccurredAt: now, MatchID: view.MatchID, ServerID: view.ServerID, PlayerID: view.PlayerID}
+}
+
 type rankedProfileResponse struct {
 	Rating      float64 `json:"rating"`
 	RD          float64 `json:"rd"`

server/api/service_test.go

@@ -983,3 +983,19 @@ func TestAssignmentRecoveryIsPlayerScopedAndRejectsExpiredOrMismatchedViews(t *t
 		t.Fatalf("expired assignment status=%d", status)
 	}
 }
+
+func TestAssignmentEventUsesAuthoritativeRevisionWithoutChangingResponseShape(t *testing.T) {
+	now := time.Unix(1000, 0).UTC()
+	view := AssignmentView{MatchID: "match-1", ServerID: "server-1", PlayerID: "player-a", Revision: 7}
+	event := assignmentChangedEvent(view, now)
+	if event.Revision != 7 || event.ResourceID != "match-1" || event.PlayerID != "player-a" {
+		t.Fatalf("assignment event = %+v", event)
+	}
+	payload, err := json.Marshal(view)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if strings.Contains(string(payload), "revision") {
+		t.Fatalf("assignment response leaked event revision: %s", payload)
+	}
+}

server/api/store_adapters.go

@@ -27,6 +27,7 @@ func AssignmentProviderFromStore(db *sql.DB) AssignmentProvider {
 			ProtocolVersion:   assignment.ProtocolVersion,
 			Transport:         assignment.Transport,
 			JoinAuthorisation: assignment.JoinAuthorisation,
+			Revision:          assignment.Revision,
 		}, nil
 	}
 }