Improve dashboard maintainability before the next release

The dashboard had several oversized orchestration, component, and CSS files that made product-copy changes and mobile/performance work risky. This refactor preserves behavior while splitting scan terminal CSS, opportunity helpers, future forecast panels, history/detail charts, and probability/model sections into smaller ownership boundaries.

Constraint: No user-visible version bump because this batch is architecture and performance cleanup, not a release announcement.

Rejected: Rewrite dashboard state management in the same batch | too broad for a safe upload after CSS and component splitting.

Confidence: high

Scope-risk: moderate

Reversibility: clean

Directive: Keep new component/CSS boundaries instead of moving product copy back into the large dashboard files.

Tested: npm run build; npm run test:business; git diff --check

Not-tested: Browser visual smoke test after push

frontend/components/dashboard/scan-terminal/OpportunityOverview.tsx

@@ -93,7 +93,7 @@ const OpportunityDecisionCard = memo(function OpportunityDecisionCard({
   );
 });
 
-export function OpportunityOverview({
+export const OpportunityOverview = memo(function OpportunityOverview({
   rows,
   terminalData,
   loading,
@@ -212,5 +212,5 @@ export function OpportunityOverview({
       </div>
     </div>
   );
-}
+});