Phase 3a: shadcn init + Home/Case List view

Initialize shadcn/ui (radix-nova preset) and wire its semantic tokens
to the editorial navy/cream/gold palette so primitives inherit the
judicial voice without per-component overrides.

Replace the Phase 2 live-probe with a real dashboard: KPI tiles,
conic-gradient status donut (ported from the vanilla renderHero),
and a TanStack Table cases list with search + sort. Add useCase(n)
hook with 5s staleTime/refetchInterval to replace the old manual
polling loop when Case Detail ships next.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

web-ui/src/lib/api/cases.ts

@@ -34,6 +34,23 @@ export type Case = {
   expected_outcome?: string | null;
   created_at?: string;
   updated_at?: string;
+  /* Present when loaded with detail=true */
+  document_count?: number;
+  processing_count?: number;
+  committee_type?: string | null;
+  hearing_date?: string | null;
+};
+
+export type CaseDetail = Case & {
+  documents?: Array<{
+    id: number | string;
+    filename: string;
+    category?: string | null;
+    status?: string;
+    uploaded_at?: string;
+    size_bytes?: number;
+  }>;
+  blocks?: Array<{ code: string; status?: string; char_count?: number }>;
 };
 
 export const casesKeys = {
@@ -52,3 +69,15 @@ export function useCases(detail = false) {
       }),
   });
 }
+
+export function useCase(caseNumber: string | undefined) {
+  return useQuery({
+    queryKey: casesKeys.detail(caseNumber ?? ""),
+    queryFn: ({ signal }) =>
+      apiRequest<CaseDetail>(`/api/cases/${caseNumber}`, { signal }),
+    enabled: Boolean(caseNumber),
+    /* Replaces the old 5s polling from vanilla index.html */
+    staleTime: 5_000,
+    refetchInterval: 5_000,
+  });
+}