refactor(admin): split multi-tenant page.tsx into colocated components

Extract types, constants, helpers, and UI pieces (LoadingSkeleton,
EmptyState, StatCard, ComplianceRing, Modal, TenantCard,
CreateTenantModal, EditTenantModal, TenantDetailModal) into
_components/ and _types.ts to bring page.tsx from 1663 LOC to
432 LOC (under the 500 hard cap). Behavior preserved.

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

admin-compliance/app/sdk/multi-tenant/_components/StatCard.tsx

@@ -0,0 +1,51 @@
+'use client'
+
+import React from 'react'
+
+export function StatCard({
+  label,
+  value,
+  icon,
+  color,
+}: {
+  label: string
+  value: string | number
+  icon: React.ReactNode
+  color: 'indigo' | 'green' | 'blue' | 'red'
+}) {
+  const colorMap = {
+    indigo: {
+      iconBg: 'bg-indigo-100',
+      iconText: 'text-indigo-600',
+      valueBg: '',
+    },
+    green: {
+      iconBg: 'bg-green-100',
+      iconText: 'text-green-600',
+      valueBg: '',
+    },
+    blue: {
+      iconBg: 'bg-blue-100',
+      iconText: 'text-blue-600',
+      valueBg: '',
+    },
+    red: {
+      iconBg: 'bg-red-100',
+      iconText: 'text-red-600',
+      valueBg: '',
+    },
+  }
+  const c = colorMap[color]
+
+  return (
+    <div className="bg-white rounded-xl border border-slate-200 p-5 hover:shadow-sm transition-shadow">
+      <div className="flex items-center gap-3 mb-3">
+        <div className={`w-10 h-10 rounded-lg ${c.iconBg} flex items-center justify-center`}>
+          <span className={c.iconText}>{icon}</span>
+        </div>
+        <span className="text-sm font-medium text-slate-500">{label}</span>
+      </div>
+      <div className="text-2xl font-bold text-slate-900">{value}</div>
+    </div>
+  )
+}