Histogram clinical control options list generated incorrectly for mapped variants

[bencap]

Bug Description

When fetching the histogram clinical control options via the API, the generated options list is currently based on the linkages from all mapped variants, rather than just those relevant to the current variants.

Expected Behavior

• When requesting histogram clinical control options, only the current set of mapped variants should be used to generate the options list.

Actual Behavior

• The options list is generated from linkages across all mapped variants in the database, not restricted to those which are current.

Steps to Reproduce

1. Fetch histogram clinical control options for a set of mapped variants via the API.
2. Observe that the options list contains controls linked to variants outside the current set.

Impact

• This can result in misleading or extraneous clinical control options being displayed, decreasing API accuracy.

Suggested Fix

• Restrict the options list generation to only the linkages relevant to the currently requested mapped variants.