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/ScanTerminalCalendar.module.css

@@ -13,6 +13,8 @@
   border-radius: 18px;
   background: rgba(8, 17, 30, 0.8);
   overflow: hidden;
+  content-visibility: auto;
+  contain-intrinsic-size: 460px;
 }
 
 .root :global(.scan-calendar-group-head) {