refactor(admin): split evidence, import, portfolio pages

Extract components and hooks from oversized pages into colocated
_components/ and _hooks/ subdirectories to enforce the 500-LOC hard cap.
page.tsx files reduced to 205, 121, and 136 LOC respectively.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

admin-compliance/app/sdk/evidence/_components/LoadingSkeleton.tsx

@@ -0,0 +1,19 @@
+'use client'
+
+export function LoadingSkeleton() {
+  return (
+    <div className="space-y-4">
+      {[1, 2, 3].map(i => (
+        <div key={i} className="bg-white rounded-xl border border-gray-200 p-6 animate-pulse">
+          <div className="flex items-start gap-4">
+            <div className="w-12 h-12 bg-gray-200 rounded-lg" />
+            <div className="flex-1">
+              <div className="h-6 w-3/4 bg-gray-200 rounded mb-2" />
+              <div className="h-4 w-full bg-gray-100 rounded" />
+            </div>
+          </div>
+        </div>
+      ))}
+    </div>
+  )
+}