chore: aktuellen Live-Stand sichern (Admin-API, Services, Auth-Erweiterungen)

Sichert den bisher uncommitteten Produktionsstand des Kundenbereich-Servers,
damit kuenftige Deploys (git reset --hard) nichts mehr verwerfen.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

server/services/invoiceNinja.js

@@ -0,0 +1,81 @@
+import { config } from '../config.js'
+
+function getPrimaryContact(client) {
+  const contacts = client?.contacts || []
+  return contacts.find((c) => c.is_primary) || contacts[0] || {}
+}
+
+export function sanitizeInvoiceClient(client) {
+  const contact = getPrimaryContact(client)
+  const baseUrl = config.invoiceNinja.url
+
+  return {
+    id: client.id,
+    number: client.number || '',
+    displayName: client.display_name || client.name || '',
+    companyName: client.name || '',
+    website: client.website || '',
+    phone: contact.phone || client.phone || '',
+    email: contact.email || '',
+    contactFirstName: contact.first_name || '',
+    contactLastName: contact.last_name || '',
+    address1: client.address1 || '',
+    address2: client.address2 || '',
+    city: client.city || '',
+    state: client.state || '',
+    postalCode: client.postal_code || '',
+    countryId: client.country_id || '',
+    vatNumber: client.vat_number || '',
+    idNumber: client.id_number || '',
+    balance: Number(client.balance ?? 0),
+    paidToDate: Number(client.paid_to_date ?? 0),
+    publicNotes: client.public_notes || '',
+    privateNotes: client.private_notes || '',
+    editUrl: `${baseUrl}/clients/${client.id}/edit`,
+  }
+}
+
+export async function listInvoiceNinjaClients() {
+  const token = config.invoiceNinja.apiToken
+  if (!token) {
+    const error = new Error('INVOICE_NINJA_API_TOKEN ist nicht konfiguriert')
+    error.status = 503
+    throw error
+  }
+
+  const clients = []
+  let page = 1
+  let totalPages = 1
+
+  while (page <= totalPages) {
+    const url = new URL(`${config.invoiceNinja.url}/api/v1/clients`)
+    url.searchParams.set('per_page', '100')
+    url.searchParams.set('page', String(page))
+    url.searchParams.set('include', 'contacts')
+
+    const response = await fetch(url, {
+      headers: {
+        'X-API-TOKEN': token,
+        'X-Requested-With': 'XMLHttpRequest',
+        Accept: 'application/json',
+      },
+    })
+
+    const data = await response.json().catch(() => ({}))
+    if (!response.ok) {
+      const error = new Error(data.message || 'Invoice Ninja API Fehler')
+      error.status = response.status === 401 ? 502 : response.status
+      throw error
+    }
+
+    const batch = (data.data || []).filter((c) => !c.is_deleted)
+    clients.push(...batch.map(sanitizeInvoiceClient))
+
+    totalPages = Number(data.meta?.pagination?.total_pages || 1)
+    page += 1
+  }
+
+  return clients.sort((a, b) =>
+    (a.displayName || a.companyName).localeCompare(b.displayName || b.companyName, 'de')
+  )
+}