Custom Aggregate Function Not Updating Correctly in Influxdb UI When Set Using the ConfigBuilder API

__Steps to reproduce:__

1. Update a cell using the influxdb-client Typescript API. Set the aggregate function to be anything other than mean, median, or last (for example count). Use the builder QueryEditMode.
2. Go to that dashboard in influxdb UI.
3. Open the configuration in builder mode

__Expected behaviour:__

The aggregate function is set to **custom->count** and data is shown correctly.

__Actual behaviour:__

Data is shown correctly (shows count data), but the aggregate function is set to **auto->mean**

__Environment info:__

Influx version 2.7.5

Start with the influxdb-client TypeScript API flow that writes aggregate functions through QueryEditMode, then inspect how the dashboard builder reads that configuration. Reproduce the custom-count case and compare the stored or returned value with the UI's auto-mean selection; done means the builder displays custom-count while showing the correct data.

Written by the indexing model from the issue text.