refactor(admin): split obligations page.tsx into colocated components

Extract ObligationModal, ObligationDetail, ObligationCard, ObligationsHeader,
StatsGrid, FilterBar and InfoBanners into _components/, plus _types.ts for
shared types/constants. page.tsx drops from 987 to 325 LOC, below the 300
soft target region and well under the 500 hard cap.

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

admin-compliance/app/sdk/obligations/_components/StatsGrid.tsx

@@ -0,0 +1,23 @@
+'use client'
+
+import React from 'react'
+import type { ObligationStats } from '../_types'
+
+export default function StatsGrid({ stats }: { stats: ObligationStats | null }) {
+  const items = [
+    { label: 'Ausstehend',    value: stats?.pending     ?? 0, color: 'text-gray-600',  border: 'border-gray-200' },
+    { label: 'In Bearbeitung',value: stats?.in_progress ?? 0, color: 'text-blue-600',  border: 'border-blue-200' },
+    { label: 'Ueberfaellig',  value: stats?.overdue     ?? 0, color: 'text-red-600',   border: 'border-red-200'  },
+    { label: 'Abgeschlossen', value: stats?.completed   ?? 0, color: 'text-green-600', border: 'border-green-200'},
+  ]
+  return (
+    <div className="grid grid-cols-2 md:grid-cols-4 gap-4">
+      {items.map(s => (
+        <div key={s.label} className={`bg-white rounded-xl border ${s.border} p-5`}>
+          <div className={`text-xs ${s.color}`}>{s.label}</div>
+          <div className={`text-3xl font-bold mt-1 ${s.color}`}>{s.value}</div>
+        </div>
+      ))}
+    </div>
+  )
+}