feat: 5-tab agent UI — PDF export, compare, auth test, all proxies

- 5 tabs: Schnellanalyse, Website-Scan, Cookie-Test, Vergleich, Login-Test
- PDF download button in ScanResult
- CompareResult: side-by-side compliance comparison table
- AuthTestResult: 5 post-login checks with legal refs
- API proxies: /scans/pdf, /compare, /authenticated-scan
- Compare: textarea for 2-5 URLs, parallel scanning

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

admin-compliance/app/api/sdk/v1/agent/compare/route.ts

@@ -0,0 +1,20 @@
+import { NextRequest, NextResponse } from 'next/server'
+const BACKEND_URL = process.env.BACKEND_API_URL || 'http://backend-compliance:8002'
+
+export async function POST(request: NextRequest) {
+  try {
+    const body = await request.text()
+    const response = await fetch(`${BACKEND_URL}/api/compliance/agent/compare`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body,
+      signal: AbortSignal.timeout(300000),
+    })
+    if (!response.ok) {
+      return NextResponse.json({ error: `Backend: ${response.status}` }, { status: response.status })
+    }
+    return NextResponse.json(await response.json())
+  } catch (error) {
+    return NextResponse.json({ error: 'Vergleich fehlgeschlagen' }, { status: 503 })
+  }
+}