Add round-type-specific observer reports with dynamic tabs

Refactor the observer reports page from a static 3-tab layout to a
dynamic tab system that adapts to each round type (INTAKE, FILTERING,
EVALUATION, SUBMISSION, MENTORING, LIVE_FINAL, DELIBERATION). Adds a
persistent Global tab for edition-wide analytics, juror score heatmap,
expandable juror assignment rows, filtering screening bar, and
deliberation results with tie detection.

- Add 5 observer proxy procedures to analytics router
- Create JurorScoreHeatmap, ExpandableJurorTable, FilteringScreeningBar
- Create 8 round-type tab components + GlobalAnalyticsTab
- Reduce reports page from 914 to ~190 lines (thin dispatcher)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/observer/reports/mentoring-report-tabs.tsx

@@ -0,0 +1,29 @@
+'use client'
+
+import { trpc } from '@/lib/trpc/client'
+import { Skeleton } from '@/components/ui/skeleton'
+import { StatusBreakdownChart } from '@/components/charts'
+import { RoundTypeStatsCards } from '@/components/observer/round-type-stats'
+
+interface MentoringReportTabsProps {
+  roundId: string
+  programId: string
+}
+
+function StatusBreakdownSection({ roundId }: { roundId: string }) {
+  const { data: statusBreakdown, isLoading } =
+    trpc.analytics.getStatusBreakdown.useQuery({ roundId })
+
+  if (isLoading) return <Skeleton className="h-[350px]" />
+  if (!statusBreakdown) return null
+  return <StatusBreakdownChart data={statusBreakdown} />
+}
+
+export function MentoringReportTabs({ roundId }: MentoringReportTabsProps) {
+  return (
+    <div className="space-y-6">
+      <RoundTypeStatsCards roundId={roundId} />
+      <StatusBreakdownSection roundId={roundId} />
+    </div>
+  )
+}