fix(frontend): remove exhaustive-deps suppression from Findings virtualizer effect

[SathvikaSingoti]

Description

Removes the eslint-disable react-hooks/exhaustive-deps suppression on the Findings virtualizer scroll effect. The effect previously read selectedFinding, virtualRows, and virtualizer from render scope while only depending on selectedFindingId, which could leave stale virtualizer/row data after filtering or sorting. Fixed by keeping selectedFindingId as the only reactive dependency, while virtualRows and virtualizer are now read through refs kept fresh via separate no-dependency-array effects, satisfying exhaustive-deps without over-firing the scroll on every filter/sort.

Related Issues

Closes #1407

Type of Change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

• Added a regression test covering selection changing after a sort-order change, verifying scrollToIndex is called with the correct post-sort index rather than a stale pre-sort one.
• Ran full frontend suite: npm run test - 531/531 passing.
• Ran npm run typecheck - no errors.
• Ran npm run build - succeeds (pre-existing vendor chunk size warning is unrelated to this change).
• Ran scripts/check-artifacts.sh - all clear, no generated artifacts staged.

Checklist

• My code follows the code style of this project.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.