feat(cmp): unified consent view — Website-Besucher + Login-Nutzer tabs

Merges two separate consent views into one unified page at /sdk/einwilligungen:
- Tab "Website-Besucher": device-based banner consents with site selector
- Tab "Login-Nutzer": user-based DSGVO consents (existing, unchanged)

Backend:
- New endpoint GET /admin/consents for paginated banner consent records
- Fix: categories JSON string parsing (was iterating chars instead of array)

CMP Dashboard:
- Dynamic site selector replacing hardcoded "preview-test-site"

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

admin-compliance/app/sdk/einwilligungen/_hooks/useBannerConsents.ts

@@ -0,0 +1,73 @@
+import { useState, useEffect, useCallback } from 'react'
+import { BannerConsentRecord, BannerConsentStats, BannerSite, PAGE_SIZE } from '../_types'
+
+const BANNER_API = '/api/sdk/v1/banner'
+const TENANT_ID = '9282a473-5c95-4b3a-bf78-0ecc0ec71d3e'
+const HEADERS = { 'x-tenant-id': TENANT_ID }
+
+function fb(path: string) {
+  return fetch(`${BANNER_API}/${path}`, { headers: HEADERS })
+    .then(r => r.ok ? r.json() : null)
+    .catch(() => null)
+}
+
+export function useBannerConsents() {
+  const [records, setRecords] = useState<BannerConsentRecord[]>([])
+  const [sites, setSites] = useState<BannerSite[]>([])
+  const [selectedSite, setSelectedSite] = useState<string>('')
+  const [stats, setStats] = useState<BannerConsentStats | null>(null)
+  const [currentPage, setCurrentPage] = useState(1)
+  const [totalRecords, setTotalRecords] = useState(0)
+  const [loading, setLoading] = useState(true)
+
+  // Load sites on mount
+  useEffect(() => {
+    fb('admin/sites').then(data => {
+      const list = Array.isArray(data) ? data : []
+      setSites(list)
+      if (list.length > 0) {
+        setSelectedSite(list[0].site_id)
+      }
+      setLoading(false)
+    })
+  }, [])
+
+  // Load consents + stats when site or page changes
+  const loadData = useCallback(async () => {
+    if (!selectedSite) return
+    setLoading(true)
+    const offset = (currentPage - 1) * PAGE_SIZE
+    const [consentsData, statsData] = await Promise.all([
+      fb(`admin/consents?site_id=${selectedSite}&limit=${PAGE_SIZE}&offset=${offset}`),
+      fb(`admin/stats/${selectedSite}`),
+    ])
+    if (consentsData) {
+      setRecords(consentsData.consents || [])
+      setTotalRecords(consentsData.total || 0)
+    }
+    setStats(statsData)
+    setLoading(false)
+  }, [selectedSite, currentPage])
+
+  useEffect(() => {
+    loadData()
+  }, [loadData])
+
+  const changeSite = (siteId: string) => {
+    setSelectedSite(siteId)
+    setCurrentPage(1)
+  }
+
+  return {
+    records,
+    sites,
+    selectedSite,
+    changeSite,
+    stats,
+    currentPage,
+    setCurrentPage,
+    totalRecords,
+    loading,
+    reload: loadData,
+  }
+}