Row total disappear when Pivot table is added to a Dashboard

### Describe the bug

Row totals fail to render in a Pivot table at dashboard level sometimes, but work well when they the pivot is at card level. This happened after upgrading from 56 to 57

Internal thread with Query responses and more context [here](https://metaboat.slack.com/archives/C05MPF0TM3L/p1766166091138289)

### To Reproduce

No deterministic repro steps, unfortunately, but it was reported by a customer [here](https://app.usepylon.com/issues/views/663f0f78-70ed-4cfa-8ea0-6f97128e13c8?conversationID=e856f6bf-02ca-4f18-9fc8-e36e1c3c0426)

### Expected behavior

_No response_

### Logs

_No response_

### Information about your Metabase installation

```JSON
-v1.57.7
```

### Severity

p2

### Additional context

_No response_

Start by investigating how dashboard-level Pivot tables render row totals and compare that behavior with the card-level case. Use the reported upgrade from v1.56 to v1.57.7 and the linked internal context to look for more reproduction details. Done means row totals render reliably in dashboard-level Pivot tables.

Written by the indexing model from the issue text.