feat: Package 4 Phase 2 — Frontend-Fixes und Backend-Endpoints vervollständigt

- document-generator: STEP_EXPLANATIONS Key 'consent' → 'document-generator'
- Proxy: Content-Type nicht mehr hardcoded; forwarded vom Client (Fix für DOCX-Upload + multipart/arrayBuffer)
- Backend: GET /documents/{id}, DELETE /documents/{id}, GET /versions/{id} ergänzt
- Backend-Tests: 4 neue Tests für die neuen Endpoints
- consent/page.tsx: Create-Modal + handleCreateDocument() + DELETE-Handler verdrahtet
- einwilligungen/page.tsx: odentifier→identifier, ip_address, user_agent, history aus API gemappt; source nullable
- cookie-banner/page.tsx: handleExportCode() + Toast für 'Code exportieren' Button
- workflow/page.tsx: 'Neues Dokument' Button + createDocument() + Modal

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

admin-compliance/app/(sdk)/sdk/cookie-banner/page.tsx

@@ -222,6 +222,7 @@ export default function CookieBannerPage() {
   const [categories, setCategories] = useState<CookieCategory[]>([])
   const [config, setConfig] = useState<BannerConfig>(defaultConfig)
   const [isSaving, setIsSaving] = useState(false)
+  const [exportToast, setExportToast] = useState<string | null>(null)
 
   React.useEffect(() => {
     const loadConfig = async () => {
@@ -263,6 +264,25 @@ export default function CookieBannerPage() {
     }
   }
 
+  const handleExportCode = async () => {
+    try {
+      const res = await fetch('/api/sdk/v1/einwilligungen/cookie-banner/embed-code')
+      if (res.ok) {
+        const data = await res.json()
+        const code = data.embed_code || data.script || ''
+        await navigator.clipboard.writeText(code)
+        setExportToast('Embed-Code in Zwischenablage kopiert!')
+        setTimeout(() => setExportToast(null), 3000)
+      } else {
+        setExportToast('Fehler beim Laden des Embed-Codes')
+        setTimeout(() => setExportToast(null), 3000)
+      }
+    } catch {
+      setExportToast('Fehler beim Kopieren in die Zwischenablage')
+      setTimeout(() => setExportToast(null), 3000)
+    }
+  }
+
   const handleSaveConfig = async () => {
     setIsSaving(true)
     try {
@@ -288,6 +308,13 @@ export default function CookieBannerPage() {
 
   return (
     <div className="space-y-6">
+      {/* Toast notification */}
+      {exportToast && (
+        <div className="fixed top-4 right-4 z-50 bg-gray-900 text-white px-4 py-2 rounded-lg shadow-lg text-sm">
+          {exportToast}
+        </div>
+      )}
+
       {/* Step Header */}
       <StepHeader
         stepId="cookie-banner"
@@ -297,7 +324,10 @@ export default function CookieBannerPage() {
         tips={stepInfo.tips}
       >
         <div className="flex items-center gap-2">
-          <button className="px-4 py-2 text-gray-600 hover:bg-gray-100 rounded-lg transition-colors">
+          <button
+            onClick={handleExportCode}
+            className="px-4 py-2 text-gray-600 hover:bg-gray-100 rounded-lg transition-colors"
+          >
             Code exportieren
           </button>
           <button