feat: Google Consent Mode v2 + Developer Portal cookie banner docs

Phase A: Google Consent Mode v2 in cookie-banner-embed.ts
- gtag('consent', 'default', {...denied}) before banner loads
- gtag('consent', 'update', {...}) after user decision
- Automatic mapping: statistics→analytics_storage, marketing→ad_storage

Phase B: 5 Developer Portal pages at /sdk/consent/cookie-banner/
- Overview page with 4 cards
- Integration Guide: 3-step setup, script-tag, categories
- Google Consent Mode: automatic integration, parameter mapping
- Script Blocking: type=text/plain pattern, GA/FB/Hotjar examples
- Compliance Checklist: 12 points, 9 automatic

Sidebar navigation extended with Cookie-Banner section.

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

admin-compliance/lib/sdk/einwilligungen/generator/cookie-banner-embed.ts

@@ -325,6 +325,29 @@ function generateJS(config: CookieBannerConfig): string {
   const CATEGORIES = ${JSON.stringify(categoryIds)};
   const REQUIRED_CATEGORIES = ${JSON.stringify(requiredCategories)};
 
+  // Google Consent Mode v2 — PFLICHT seit Maerz 2024 fuer Google Services in EEA
+  // Sets default consent state to "denied" BEFORE any Google tags fire
+  if (typeof gtag === 'function') {
+    gtag('consent', 'default', {
+      analytics_storage: 'denied',
+      ad_storage: 'denied',
+      ad_user_data: 'denied',
+      ad_personalization: 'denied',
+      functionality_storage: 'granted',
+      security_storage: 'granted',
+    });
+  }
+
+  function updateGoogleConsentMode(consent) {
+    if (typeof gtag !== 'function') return;
+    gtag('consent', 'update', {
+      analytics_storage: consent.statistics ? 'granted' : 'denied',
+      ad_storage: consent.marketing ? 'granted' : 'denied',
+      ad_user_data: consent.marketing ? 'granted' : 'denied',
+      ad_personalization: consent.marketing ? 'granted' : 'denied',
+    });
+  }
+
   function getConsent() {
     const cookie = document.cookie.split('; ').find(row => row.startsWith(COOKIE_NAME + '='));
     if (!cookie) return null;
@@ -342,6 +365,7 @@ function generateJS(config: CookieBannerConfig): string {
                       ';expires=' + date.toUTCString() +
                       ';path=/;SameSite=Lax';
     window.dispatchEvent(new CustomEvent('cookieConsentUpdated', { detail: consent }));
+    updateGoogleConsentMode(consent);
   }
 
   function hasConsent(category) {