Add more info dialog opened and closed external bus messages

The more info dialog now reports the entity it is showing over the
external bus, so the companion app knows what the frontend displays.

Author: claude

src/dialogs/more-info/ha-more-info-dialog.ts

@@ -1031,6 +1031,32 @@ export class MoreInfoDialog extends DirtyStateProviderMixin<
       this._infoEditMode = false;
       this._detailsYamlMode = false;
     }
+
+    if (changedProps.has("_entityId")) {
+      this._reportShownEntityToExternalApp(
+        changedProps.get("_entityId") as string | null | undefined
+      );
+    }
+  }
+
+  private _reportShownEntityToExternalApp(
+    previousEntityId: string | null | undefined
+  ) {
+    const external = this.hass.auth.external;
+    if (!external) {
+      return;
+    }
+    if (this._entityId) {
+      external.fireMessage({
+        type: "more_info/opened",
+        payload: { entity_id: this._entityId },
+      });
+    } else if (previousEntityId) {
+      external.fireMessage({
+        type: "more_info/closed",
+        payload: { entity_id: previousEntityId },
+      });
+    }
   }
 
   private _entryUpdated(ev: CustomEvent<ExtEntityRegistryEntry>) {

src/external_app/external_messaging.ts

@@ -184,6 +184,20 @@ interface EMOutgoingMessageAddEntityTo extends EMMessage {
   };
 }
 
+interface EMOutgoingMessageMoreInfoOpened extends EMMessage {
+  type: "more_info/opened";
+  payload: {
+    entity_id: string;
+  };
+}
+
+interface EMOutgoingMessageMoreInfoClosed extends EMMessage {
+  type: "more_info/closed";
+  payload: {
+    entity_id: string;
+  };
+}
+
 interface EMOutgoingMessageFocusElement extends EMMessage {
   type: "focus_element";
   payload: {
@@ -216,6 +230,8 @@ type EMOutgoingMessageWithoutAnswer =
   | EMOutgoingMessageHaptic
   | EMOutgoingMessageImportThreadCredentials
   | EMOutgoingMessageMatterCommission
+  | EMOutgoingMessageMoreInfoOpened
+  | EMOutgoingMessageMoreInfoClosed
   | EMOutgoingMessageSidebarShow
   | EMOutgoingMessageTagWrite
   | EMOutgoingMessageThemeUpdate