feat(admin): Tab "Browser-Verhalten" — Per-Browser-Matrix + Screenshots (Phase 3)

- BrowserBehaviorView: laedt gespeicherte Matrix (GET), sonst "Browser-Test
  starten" (POST run, Live-Lauf). Per-Browser-Tabelle (Cookies vor Consent /
  nach Ablehnen / Ablehnen respektiert / Oberflaeche / Score), Engine-Detail
  mit Banner-Screenshot + Oberflaechen-Befunden, Mobil-Badge, "nicht
  verfuegbar"-Zeilen fuer fehlende Browser (arm64-Dev).
- Proxys browser-behavior (GET) + browser-behavior/run (POST, langer Timeout).
- page.tsx: Tab "Browser-Verhalten" (sichtbar sobald scanbare URL im Snapshot).
- consent-tester scan_matrix_summary: banner_findings je Engine im summary
  (Text/Severity/Norm) → Oberflaechen-Befunde im Tab.
- tsc strict clean; Vitest BrowserBehaviorView (2).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

admin-compliance/app/sdk/agent/snapshots/[snapshotId]/page.tsx

@@ -15,6 +15,7 @@ import { CookieLibraryPanel } from '../../_components/CookieLibraryPanel'
 import { CookieDeclarationDiff } from '../../_components/CookieDeclarationDiff'
 import { CookieResultView } from '../../_components/CookieResultView'
 import { AgentModuleTab } from '../../_components/AgentModuleTab'
+import { BrowserBehaviorView } from '../../_components/BrowserBehaviorView'
 
 export default function SnapshotDetail(
   { params }: { params: Promise<{ snapshotId: string }> },
@@ -53,12 +54,16 @@ export default function SnapshotDetail(
   const hasCookies = (snap?.cmp_vendors?.length ?? 0) > 0
   const hasDoc = (dt: string) => docs.some(
     (e: any) => e.doc_type === dt && (e.text || e.content || '').length > 100)
+  // Browser-Verhalten braucht nur eine scanbare URL (on-demand-Live-Lauf).
+  const hasSite = docs.some((e: any) => (e.url || '').trim())
+    || (!!snap?.site_domain && snap.site_domain !== 'unknown')
 
   const modules = useMemo(() => [
     ...(hasCookies ? [{ key: 'cookie', label: 'Cookies & Tracking' }] : []),
     ...(hasDoc('impressum') ? [{ key: 'impressum', label: 'Impressum' }] : []),
     ...(hasDoc('dse') ? [{ key: 'dse', label: 'Datenschutzerklärung' }] : []),
     ...(hasDoc('agb') ? [{ key: 'agb', label: 'AGB' }] : []),
+    ...(hasSite ? [{ key: 'browser', label: 'Browser-Verhalten' }] : []),
     // eslint-disable-next-line react-hooks/exhaustive-deps
   ], [snap])
 
@@ -133,6 +138,10 @@ export default function SnapshotDetail(
           {tab === 'agb' && (
             <AgentModuleTab snapshotId={snapshotId} docType="agb" label="AGB" />
           )}
+
+          {tab === 'browser' && (
+            <BrowserBehaviorView snapshotId={snapshotId} />
+          )}
         </>
       )}
     </div>