feat(preprod): Sort insight diff by total potential savings

[mtopo27]

Summary

• Sort insights by total_savings_change descending within each tab of the insight diff, so the biggest opportunities surface first
• Applies per-tab, meaning "unresolved" and "resolved" tabs sort by their recalculated values
• Affects both the build comparison page and the issue details insight diff section

Fixes EME-997

Test plan

• Open a build comparison page with multiple insights and verify they are sorted by savings descending
• Switch between tabs (All, New, Unresolved, Resolved) and confirm each tab is independently sorted
• Verify the issue details insight diff section also shows sorted insights

[linear-code]

EME-997 Sort insight diff by total potential savings

[sentry]

Bug: The sorting logic incorrectly orders the "Resolved" tab by placing the smallest savings first, because it performs a descending sort on negative total_savings_change values.
_{Severity: MEDIUM}

Suggested Fix

Update the sorting logic to handle the "Resolved" tab as a special case. For insights in the "Resolved" tab, sort in ascending order of total_savings_change (e.g., a.total_savings_change - b.total_savings_change) to ensure the largest savings (most negative numbers) appear first.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent.
Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not
valid.

Location:
static/app/views/preprod/buildComparison/main/insightComparisonSection.tsx#L153-L155

Potential issue: The code at `insightComparisonSection.tsx:153~155` applies a uniform
descending sort based on `total_savings_change` across all insight tabs. For the
"Resolved" tab, insights have negative `total_savings_change` values to represent
savings. Sorting negative numbers in descending order (e.g., -100 is greater than -5000)
causes insights with the smallest savings to appear at the top of the list. This is
contrary to the intended behavior of showing the "biggest opportunities" first. As a
result, users will see trivial fixes prioritized over major ones in the "Resolved" tab,
which degrades the feature's usefulness.

_{Did we get this right? 👍 / 👎 to inform future reviews.}

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

Bugbot Autofix prepared a fix for the issue found in the latest run.

• ✅ Fixed: Descending sort reverses order for negative resolved values
  • Updated insight sorting to use descending absolute total_savings_change, so resolved items with larger savings now rank first.

Or push these changes by commenting:

@cursor push 63e368251c

Preview (63e368251c)

diff --git a/static/app/views/preprod/buildComparison/main/insightComparisonSection.tsx b/static/app/views/preprod/buildComparison/main/insightComparisonSection.tsx
--- a/static/app/views/preprod/buildComparison/main/insightComparisonSection.tsx
+++ b/static/app/views/preprod/buildComparison/main/insightComparisonSection.tsx
@@ -151,7 +151,9 @@
     }
 
     for (const insights of Object.values(byTab)) {
-      insights.sort((a, b) => b.total_savings_change - a.total_savings_change);
+      insights.sort(
+        (a, b) => Math.abs(b.total_savings_change) - Math.abs(a.total_savings_change)
+      );
     }
 
     return {

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^{Reviewed by Cursor Bugbot for commit b900add. Configure here.}