Miner count incorrect in temperature chart

## Bug Description
 The ProtoFleet dashboard at STL is reporting 464 miners outside of safe range for the Temperature metric, but STL only has 18 physical miners connected.

 ## Observed Behavior
 - The dashboard is counting far more miners than physically exist at the STL site.

 ## Expected Behavior
 The dashboard should only report metrics for the 18 miners that actually exist at STL.

 ## Environment
 - Site: STL (http://172.16.25.19/)
 - Actual miner count: 18
 - Reported miner count: 464

Start by reproducing the temperature chart at the STL dashboard URL and compare its reported miner count with the documented 18 physical miners. Trace the data source used for that chart and verify that the result reports only miners connected to STL; done means the chart no longer reports 464 miners for the site.

Written by the indexing model from the issue text.