feat(cookie): Deklaration-vs-Bibliothek-Diff-Sicht + Funnel-KPI

Für die Library-getroffene Teilmesse (~32%) pro Cookie die Feld-
Abweichungen deklariert→Library (Kategorie/Laufzeit/Zweck) als Diff-Karte,
plus ehrlicher Funnel (gesamt → geprüft → abweichend) — nicht-getroffene
Cookies sind nicht prüfbar (kein Pass/Fail), passend zur Tonalität.

- analyze_cookies: 'expected'-Soll-Wert an tracker_as_necessary/
  excessive_lifetime/missing_purpose (+ _CAT_LABEL_DE).
- neues cookie_declaration_diff.build_declaration_diff: reine Regroup-
  Aggregation der Findings pro Cookie (single source = analyze_cookies),
  Hinweis-Typen (third_country/eu_alternative) bewusst ausgeschlossen.
- cookie-check exponiert out['declaration_diff'].
- CookieDeclarationDiff.tsx oben im Cookie-Tab (vor Panel/ResultView).

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

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

@@ -12,6 +12,7 @@ import React, { use as useUnwrap, useEffect, useMemo, useState } from 'react'
 import Link from 'next/link'
 
 import { CookieLibraryPanel } from '../../_components/CookieLibraryPanel'
+import { CookieDeclarationDiff } from '../../_components/CookieDeclarationDiff'
 import { CookieResultView } from '../../_components/CookieResultView'
 import { AgentModuleTab } from '../../_components/AgentModuleTab'
 
@@ -93,6 +94,7 @@ export default function SnapshotDetail(
 
           {tab === 'cookie' && hasCookies && (
             <div className="space-y-4">
+              <CookieDeclarationDiff data={check?.declaration_diff} />
               <CookieLibraryPanel snapshotId={snapshotId} data={check ?? undefined} />
               <CookieResultView snapshot={snap} cookieCategories={check?.cookie_categories} storageTypes={check?.storage_inventory?.per_cookie} />
             </div>