fix(iot-hub): fix dashboardId serialization in device register request

DashboardId implements EntityId which uses EntityIdDeserializer requiring
both entityType and id fields. Frontend was sending {"id":"..."} without
entityType, causing "Missing entityType or id!" 400 error.

Fix: include entityType: "DASHBOARD" in the dashboardId payload.
Add deserialization unit test to verify the exact frontend payload format.

common/data/src/test/java/org/thingsboard/server/common/data/iot_hub/DeviceInstalledItemDescriptorTest.java

@@ -0,0 +1,75 @@
+/**
+ * Copyright © 2016-2026 The Thingsboard Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.thingsboard.server.common.data.iot_hub;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.junit.jupiter.api.Test;
+import org.thingsboard.server.common.data.EntityType;
+import org.thingsboard.server.common.data.id.DashboardId;
+
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class DeviceInstalledItemDescriptorTest {
+
+    private static final ObjectMapper mapper = new ObjectMapper();
+
+    @Test
+    void deserializeFromFrontendPayload() throws Exception {
+        // Exact payload the frontend sends after the fix
+        String json = """
+                {
+                  "type": "DEVICE",
+                  "createdEntityIds": [
+                    {"entityType": "DEVICE_PROFILE", "id": "3eb9c330-2e57-11f1-9334-a385172e8e7d"},
+                    {"entityType": "DEVICE", "id": "8a90d5e0-2e5d-11f1-a802-c35a9af2ebde"},
+                    {"entityType": "DASHBOARD", "id": "8bc229f0-2e5d-11f1-a802-c35a9af2ebde"}
+                  ],
+                  "dashboardId": {"entityType": "DASHBOARD", "id": "8bc229f0-2e5d-11f1-a802-c35a9af2ebde"}
+                }
+                """;
+
+        // Deserialize the same way the controller does (JsonNode → treeToValue)
+        JsonNode node = mapper.readTree(json);
+        DeviceInstalledItemDescriptor descriptor = mapper.treeToValue(node, DeviceInstalledItemDescriptor.class);
+
+        assertThat(descriptor).isNotNull();
+        assertThat(descriptor.getCreatedEntityIds()).hasSize(3);
+        assertThat(descriptor.getCreatedEntityIds().get(0).getEntityType()).isEqualTo(EntityType.DEVICE_PROFILE);
+        assertThat(descriptor.getCreatedEntityIds().get(1).getEntityType()).isEqualTo(EntityType.DEVICE);
+        assertThat(descriptor.getCreatedEntityIds().get(2).getEntityType()).isEqualTo(EntityType.DASHBOARD);
+        assertThat(descriptor.getDashboardId()).isNotNull();
+        assertThat(descriptor.getDashboardId().getId()).isEqualTo(UUID.fromString("8bc229f0-2e5d-11f1-a802-c35a9af2ebde"));
+    }
+
+    @Test
+    void roundTripSerialization() throws Exception {
+        DeviceInstalledItemDescriptor original = new DeviceInstalledItemDescriptor();
+        DashboardId dashboardId = new DashboardId(UUID.randomUUID());
+        original.setDashboardId(dashboardId);
+        original.setCreatedEntityIds(java.util.List.of(dashboardId));
+
+        String json = mapper.writeValueAsString(original);
+        JsonNode node = mapper.readTree(json);
+        DeviceInstalledItemDescriptor deserialized = mapper.treeToValue(node, DeviceInstalledItemDescriptor.class);
+
+        assertThat(deserialized.getDashboardId().getId()).isEqualTo(original.getDashboardId().getId());
+        assertThat(deserialized.getCreatedEntityIds()).hasSize(1);
+        assertThat(deserialized.getCreatedEntityIds().get(0).getId()).isEqualTo(dashboardId.getId());
+    }
+}

ui-ngx/src/app/core/http/iot-hub-api.service.ts

@@ -114,7 +114,7 @@ export class IotHubApiService {
 
   public registerDeviceInstall(
     versionId: string,
-    descriptor: { type?: string; createdEntityIds: { entityType: string; id: string }[]; dashboardId?: { id: string } },
+    descriptor: { type?: string; createdEntityIds: { entityType: string; id: string }[]; dashboardId?: { entityType: string; id: string } },
     config?: IotHubRequestConfig
   ): Observable<InstallItemVersionResult> {
     return this.http.post<InstallItemVersionResult>(

ui-ngx/src/app/modules/home/pages/iot-hub/device-install-dialog/device-install-dialog.component.ts

@@ -498,12 +498,12 @@ export class TbDeviceInstallDialogComponent implements OnInit {
     return ids;
   }
 
-  private findCreatedDashboardId(): { id: string } | undefined {
+  private findCreatedDashboardId(): { entityType: string; id: string } | undefined {
     for (const ws of this.wizardSteps) {
       if (ws.type === 'progress' && ws.entitySteps) {
         for (const ep of ws.entitySteps) {
           if (ep.step.type === InstallStepType.DASHBOARD && ep.status === 'success' && ep.entityOutput) {
-            return { id: ep.entityOutput.id };
+            return { entityType: 'DASHBOARD', id: ep.entityOutput.id };
           }
         }
       }