Add Today dashboard foundation with permission-aware KPI summary API.

Replace hardcoded Today cards with a backend summary endpoint and composable frontend widgets filtered by org type and tab permissions.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/components/today/KpiCard.tsx

@@ -0,0 +1,47 @@
+import { Card } from '@/components/ui/shared/Card';
+import type { KpiCardColor } from '@/components/today/widget-registry';
+import type { LucideIcon } from 'lucide-react';
+
+const colorClasses: Record<KpiCardColor, string> = {
+  blue: '!bg-purpose-visit-bg !text-purpose-visit-fg !border-purpose-visit-border',
+  yellow: '!bg-badge-warning-bg !text-badge-warning-fg !border-badge-warning-border',
+  green: '!bg-badge-success-bg !text-badge-success-fg !border-badge-success-border',
+  red: '!bg-badge-danger-bg !text-badge-danger-fg !border-badge-danger-border',
+  purple: '!bg-purpose-consultation-bg !text-purpose-consultation-fg !border-purpose-consultation-border',
+  default: '',
+};
+
+interface KpiCardProps {
+  title: string;
+  value: string;
+  subtitle?: string | null;
+  icon?: LucideIcon;
+  color?: KpiCardColor;
+  loading?: boolean;
+}
+
+export function KpiCard({
+  title,
+  value,
+  subtitle,
+  icon: Icon,
+  color = 'default',
+  loading = false,
+}: KpiCardProps) {
+  return (
+    <Card className={colorClasses[color]}>
+      <div className="flex items-start justify-between gap-3">
+        <p className="text-sm font-medium">{title}</p>
+        {Icon ? <Icon className="h-4 w-4 shrink-0 opacity-80" aria-hidden /> : null}
+      </div>
+      {loading ? (
+        <div className="mt-2 h-8 w-16 animate-pulse rounded bg-current/10" />
+      ) : (
+        <p className="text-2xl font-bold mt-2">{value}</p>
+      )}
+      {subtitle ? (
+        <p className="text-xs opacity-80 mt-1">{subtitle}</p>
+      ) : null}
+    </Card>
+  );
+}