feat(browser-matrix): Cross-Browser-Befunde + Browser-Default-Einordnung (Phase 4)

- browser_cross_finding: deterministische Sicht ueber die Matrix (keine 2.
  Engine, kein LLM). Findet Inkonsistenzen ZWISCHEN Browsern (Cookies vor
  Consent / Ablehnen nicht universell respektiert / Banner-Links fehlend) und
  ordnet ein: Safari-ITP / Brave-Shields / Firefox-ETP maskieren Verstoesse
  clientseitig → strenge Engine "sauber" ist KEIN Compliance-Beleg, massgeblich
  sind die nachgiebigen (Chrome/Edge). Coverage-Hinweis fuer nicht verfuegbare
  Browser. Je Befund Titel/Detail/Severity/affected/Massnahme.
- snapshot_check_routes: cross_findings frisch in run + GET (nicht persistiert).
- BrowserBehaviorView: "Cross-Browser-Befunde"-Block ueber der Tabelle.
- Tests: test_browser_cross_finding (6).

Offen (Folge-Task): Borlabs-Consent-Historie-Live-Erkennung (braucht
consent-tester-Storage-Scan).

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

admin-compliance/app/sdk/agent/_components/BrowserBehaviorView.tsx

@@ -22,7 +22,11 @@ type Row = {
   profile_id: string; label: string; engine?: string; is_mobile?: boolean
   score?: number; verbal?: string; summary?: Summary | null; error?: string
 }
-type Matrix = { browser_matrix?: Row[]; aggregate?: Record<string, unknown>; url?: string; scanned_at?: string }
+type CrossFinding = { title: string; detail?: string; severity: string; affected?: string[]; measure?: string }
+type Matrix = {
+  browser_matrix?: Row[]; aggregate?: Record<string, unknown>
+  url?: string; scanned_at?: string; cross_findings?: CrossFinding[]
+}
 
 const sevCls = (s: string) => {
   const u = (s || '').toUpperCase()
@@ -119,6 +123,30 @@ export function BrowserBehaviorView({ snapshotId }: { snapshotId: string }) {
       </div>
       {error && <div className="text-sm text-red-600">{error}</div>}
 
+      {/* Cross-Browser-Befunde — der Mehrwert ggü. Einzel-Browser-Scan */}
+      {(matrix.cross_findings?.length ?? 0) > 0 && (
+        <div className="space-y-2">
+          <h3 className="text-sm font-semibold text-gray-900">Cross-Browser-Befunde</h3>
+          {matrix.cross_findings!.map((f, i) => (
+            <div key={i} className="border border-gray-200 rounded-xl p-3 space-y-1">
+              <div className="flex items-center gap-2 flex-wrap">
+                <span className={`text-[10px] px-1.5 py-0.5 rounded uppercase ${sevCls(f.severity)}`}>{f.severity}</span>
+                <span className="text-sm font-medium text-gray-900">{f.title}</span>
+              </div>
+              {f.detail && <p className="text-sm text-gray-600">{f.detail}</p>}
+              {(f.affected?.length ?? 0) > 0 && (
+                <div className="flex gap-1 flex-wrap">
+                  {f.affected!.map((a, j) => (
+                    <span key={j} className="text-[10px] px-1.5 py-0.5 rounded bg-gray-100 text-gray-600">{a}</span>
+                  ))}
+                </div>
+              )}
+              {f.measure && <p className="text-sm text-gray-700"><span className="text-gray-400">Maßnahme: </span>{f.measure}</p>}
+            </div>
+          ))}
+        </div>
+      )}
+
       <div className="overflow-x-auto border border-gray-200 rounded-xl">
         <table className="w-full text-sm">
           <thead className="bg-gray-50 text-gray-500 text-xs">