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

Split 876-LOC page.tsx into 146 LOC with 7 colocated components
(RoadmapCard, CreateRoadmapModal, CreateItemModal, ImportWizard,
RoadmapDetailView split into header + items table), plus _types.ts,
_constants.ts, and _api.ts. Behavior preserved.

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

admin-compliance/app/sdk/roadmap/_components/RoadmapDetailHeader.tsx

@@ -0,0 +1,62 @@
+import type { Roadmap, RoadmapStats } from '../_types'
+import { statusColors, statusLabels } from '../_constants'
+
+export function RoadmapDetailHeader({
+  roadmap,
+  stats,
+  onCreateItem,
+}: {
+  roadmap: Roadmap
+  stats: RoadmapStats | null
+  onCreateItem: () => void
+}) {
+  return (
+    <div className="bg-white rounded-xl border-2 border-gray-200 p-6 mb-6">
+      <div className="flex items-start justify-between mb-4">
+        <div>
+          <h2 className="text-xl font-bold text-gray-900">{roadmap.title}</h2>
+          <p className="text-sm text-gray-500 mt-1">{roadmap.description}</p>
+        </div>
+        <span className={`px-3 py-1 text-sm rounded-full ${statusColors[roadmap.status]}`}>
+          {statusLabels[roadmap.status]}
+        </span>
+      </div>
+
+      <div className="mb-4">
+        <div className="flex justify-between text-sm text-gray-500 mb-1">
+          <span>{roadmap.completed_items}/{roadmap.total_items} Items abgeschlossen</span>
+          <span>{roadmap.progress}%</span>
+        </div>
+        <div className="w-full h-3 bg-gray-100 rounded-full overflow-hidden">
+          <div className="h-full bg-purple-500 rounded-full transition-all" style={{ width: `${roadmap.progress}%` }} />
+        </div>
+      </div>
+
+      {stats && (
+        <div className="grid grid-cols-4 gap-4 mb-4">
+          <div className="bg-gray-50 rounded-lg p-3 text-center">
+            <div className="text-2xl font-bold text-red-600">{stats.overdue_items}</div>
+            <div className="text-xs text-gray-500">Ueberfaellig</div>
+          </div>
+          <div className="bg-gray-50 rounded-lg p-3 text-center">
+            <div className="text-2xl font-bold text-yellow-600">{stats.upcoming_items}</div>
+            <div className="text-xs text-gray-500">Anstehend</div>
+          </div>
+          <div className="bg-gray-50 rounded-lg p-3 text-center">
+            <div className="text-2xl font-bold text-gray-900">{stats.total_effort_days}</div>
+            <div className="text-xs text-gray-500">Aufwand (Tage)</div>
+          </div>
+          <div className="bg-gray-50 rounded-lg p-3 text-center">
+            <div className="text-2xl font-bold text-purple-600">{stats.progress}%</div>
+            <div className="text-xs text-gray-500">Fortschritt</div>
+          </div>
+        </div>
+      )}
+
+      <button onClick={onCreateItem}
+        className="px-3 py-1.5 text-sm bg-purple-600 text-white rounded-lg hover:bg-purple-700">
+        Neues Item
+      </button>
+    </div>
+  )
+}