feat(reports): shared ReportEmptyState component

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/components/reports/shared/report-empty-state.tsx

@@ -0,0 +1,39 @@
+import Link from 'next/link';
+import type { Route } from 'next';
+import type { LucideIcon } from 'lucide-react';
+
+import { Button } from '@/components/ui/button';
+
+interface ReportEmptyStateProps {
+  icon: LucideIcon;
+  title: string;
+  body: string;
+  actionLabel: string;
+  actionHref: Route;
+}
+
+/**
+ * Report-level empty state. Rendered when a report's `hasData` flag is
+ * false (the port has no underlying data at all), in place of the report
+ * body — distinct from the per-chart "no data in this window" states.
+ */
+export function ReportEmptyState({
+  icon: Icon,
+  title,
+  body,
+  actionLabel,
+  actionHref,
+}: ReportEmptyStateProps) {
+  return (
+    <div className="flex flex-col items-center justify-center rounded-lg border border-dashed border-border px-6 py-20 text-center">
+      <div className="mb-4 flex h-12 w-12 items-center justify-center rounded-full bg-muted">
+        <Icon className="h-6 w-6 text-muted-foreground" aria-hidden />
+      </div>
+      <h2 className="text-lg font-semibold text-foreground">{title}</h2>
+      <p className="mt-1.5 max-w-sm text-sm text-muted-foreground">{body}</p>
+      <Button asChild className="mt-5">
+        <Link href={actionHref}>{actionLabel}</Link>
+      </Button>
+    </div>
+  );
+}