feat: add live camera multi-device viewer mode

media/main_test.go

@@ -256,3 +256,25 @@ func TestHandleSessionGetRefreshesSessionStateFromDisk(t *testing.T) {
 		t.Fatalf("expected playback ready after refresh")
 	}
 }
+
+func TestViewerSignalReturnsConflictBeforePublisherTrackReady(t *testing.T) {
+	store, err := newSessionStore(t.TempDir())
+	if err != nil {
+		t.Fatalf("newSessionStore: %v", err)
+	}
+
+	server := newMediaServer(store)
+	session, err := store.createSession(CreateSessionRequest{UserID: "1", Title: "Viewer Pending"})
+	if err != nil {
+		t.Fatalf("createSession: %v", err)
+	}
+
+	req := httptest.NewRequest(http.MethodPost, "/media/sessions/"+session.ID+"/viewer-signal", strings.NewReader(`{"type":"offer","sdp":"mock-offer"}`))
+	req.Header.Set("Content-Type", "application/json")
+	res := httptest.NewRecorder()
+	server.routes().ServeHTTP(res, req)
+
+	if res.Code != http.StatusConflict {
+		t.Fatalf("expected viewer-signal 409 before video track is ready, got %d", res.Code)
+	}
+}