Blog categories (hasMany), shipping-address contact fields, product SKU on invoices

- Posts.categories is now hasMany — blog list/detail/live-preview render
  a comma-joined list instead of a single category.
- Checkout's "Abweichende Lieferadresse" gains optional Firma + Kontakt-
  E-Mail/Telefon fields (handed to the shipping carrier, not used for
  customer communication).
- Customer profile can now store its own shipping address (mirroring
  Customers.ts's new "Lieferadresse" tab), prefilling the checkout
  override instead of always starting blank.
- Product-level optional SKU (previously only on variants) snapshots onto
  each order item and shows up on invoices (visual + EN16931 XML),
  the confirmation email, and the account order detail page.

app/konto/bestellungen/[orderNumber]/page.tsx

@@ -120,6 +120,7 @@ export default async function KontoBestellungDetailPage({ params }: { params: Pr
           {order.hasDifferentShippingAddress && (
             <div className="flex flex-col gap-1 w-full">
               <p className="text-label text-text-muted">Lieferadresse</p>
+              {order.shippingCompanyName && <p className="text-body-sm text-text-primary">{order.shippingCompanyName}</p>}
               <p className="text-body-sm text-text-primary">
                 {order.shippingFirstName} {order.shippingLastName}
               </p>
@@ -127,6 +128,11 @@ export default async function KontoBestellungDetailPage({ params }: { params: Pr
               <p className="text-body-sm text-text-primary">
                 {order.shippingZip} {order.shippingCity}, {order.shippingCountry}
               </p>
+              {(order.shippingContactEmail || order.shippingContactPhone) && (
+                <p className="text-body-sm text-text-muted">
+                  {[order.shippingContactEmail, order.shippingContactPhone].filter(Boolean).join(" · ")}
+                </p>
+              )}
             </div>
           )}
 
@@ -145,6 +151,7 @@ export default async function KontoBestellungDetailPage({ params }: { params: Pr
                   </p>
                   {!order.kleinunternehmer && <p className="text-label text-text-muted">inkl. {item.taxRatePercent}% MwSt.</p>}
                   {item.bundleContents && <p className="text-label text-text-muted">{item.bundleContents}</p>}
+                  {item.sku && <p className="text-label text-text-muted">Art.-Nr. {item.sku}</p>}
                   {item.returnQuantity > 0 && (
                     <p className="text-label text-text-muted">davon {item.returnQuantity} zurückgesendet</p>
                   )}

app/konto/profil/components/ProfileForm.tsx

@@ -35,6 +35,10 @@ export function ProfileForm({
 }) {
   const router = useRouter();
   const [deliveryMethod, setDeliveryMethod] = useState<"address" | "packstation">(profile.deliveryMethod ?? "address");
+  const [hasDifferentShippingAddress, setHasDifferentShippingAddress] = useState(profile.hasDifferentShippingAddress);
+  const [shippingDeliveryMethod, setShippingDeliveryMethod] = useState<"address" | "packstation">(
+    profile.shippingDeliveryMethod ?? "address",
+  );
   const [error, setError] = useState<string | null>(null);
   const [success, setSuccess] = useState(false);
   const [saving, setSaving] = useState(false);
@@ -58,6 +62,21 @@ export function ProfileForm({
       country: String(form.get("country") ?? ""),
       companyName: String(form.get("companyName") ?? "") || undefined,
       vatId: String(form.get("vatId") ?? "") || undefined,
+      hasDifferentShippingAddress,
+      shippingFirstName: hasDifferentShippingAddress ? String(form.get("shippingFirstName") ?? "") : undefined,
+      shippingLastName: hasDifferentShippingAddress ? String(form.get("shippingLastName") ?? "") : undefined,
+      shippingCompanyName: hasDifferentShippingAddress ? String(form.get("shippingCompanyName") ?? "") || undefined : undefined,
+      shippingDeliveryMethod: hasDifferentShippingAddress ? shippingDeliveryMethod : undefined,
+      shippingStreet: hasDifferentShippingAddress ? String(form.get("shippingStreet") ?? "") || undefined : undefined,
+      shippingPackstationNumber: hasDifferentShippingAddress
+        ? String(form.get("shippingPackstationNumber") ?? "") || undefined
+        : undefined,
+      shippingPostNumber: hasDifferentShippingAddress ? String(form.get("shippingPostNumber") ?? "") || undefined : undefined,
+      shippingZip: hasDifferentShippingAddress ? String(form.get("shippingZip") ?? "") : undefined,
+      shippingCity: hasDifferentShippingAddress ? String(form.get("shippingCity") ?? "") : undefined,
+      shippingCountry: hasDifferentShippingAddress ? String(form.get("shippingCountry") ?? "") : undefined,
+      shippingContactEmail: hasDifferentShippingAddress ? String(form.get("shippingContactEmail") ?? "") || undefined : undefined,
+      shippingContactPhone: hasDifferentShippingAddress ? String(form.get("shippingContactPhone") ?? "") || undefined : undefined,
     };
 
     try {
@@ -91,6 +110,11 @@ export function ProfileForm({
       </p>
 
       <form onSubmit={handleSubmit} className="flex flex-col gap-4 items-start w-full">
+        {/* Explicit heading, matching /checkout's own "1. Rechnungsadresse"
+            card title — without it, this section and the "Lieferadresse"
+            one further down read as one undifferentiated form instead of
+            two distinct addresses. */}
+        <p className="font-semibold text-body-sm text-text-primary">Rechnungsadresse</p>
         <div className="flex flex-col sm:flex-row gap-4 w-full">
           <Field label="Vorname" name="firstName" type="text" defaultValue={profile.firstName} required />
           <Field label="Nachname" name="lastName" type="text" defaultValue={profile.lastName} required />
@@ -164,6 +188,111 @@ export function ProfileForm({
           </select>
         </label>
 
+        <div className="h-px bg-border w-full" />
+
+        <label className="flex gap-3 items-start w-full cursor-pointer">
+          <input
+            type="checkbox"
+            checked={hasDifferentShippingAddress}
+            onChange={(e) => setHasDifferentShippingAddress(e.target.checked)}
+            className="size-5 shrink-0 mt-0.5 rounded-xs border border-border accent-brand"
+          />
+          <span className="text-body-sm text-text-primary">
+            Abweichende Lieferadresse hinterlegen — wird beim Checkout vorgeschlagen, sobald dort "Abweichende Lieferadresse" aktiviert wird
+          </span>
+        </label>
+
+        {hasDifferentShippingAddress && (
+          <div className="flex flex-col gap-4 items-start w-full">
+            <p className="font-semibold text-body-sm text-text-primary">Lieferadresse</p>
+            <div className="flex flex-col sm:flex-row gap-4 w-full">
+              <Field label="Vorname" name="shippingFirstName" type="text" defaultValue={profile.shippingFirstName ?? ""} required />
+              <Field label="Nachname" name="shippingLastName" type="text" defaultValue={profile.shippingLastName ?? ""} required />
+            </div>
+            <Field
+              label="Firma (optional)"
+              name="shippingCompanyName"
+              type="text"
+              defaultValue={profile.shippingCompanyName ?? ""}
+              wrapperClassName="w-full"
+            />
+
+            <div className="w-full flex flex-col gap-2 items-start">
+              <span className="text-label text-text-muted">Lieferart</span>
+              <div className="flex w-full max-w-sm rounded-sm border border-border overflow-hidden">
+                <button
+                  type="button"
+                  onClick={() => setShippingDeliveryMethod("address")}
+                  aria-pressed={shippingDeliveryMethod === "address"}
+                  className={`flex-1 py-3 text-body-sm font-bold transition-colors ${shippingDeliveryMethod === "address" ? "bg-brand text-text-primary" : "text-text-muted hover:text-text-primary"}`}
+                >
+                  Lieferadresse
+                </button>
+                <button
+                  type="button"
+                  onClick={() => setShippingDeliveryMethod("packstation")}
+                  aria-pressed={shippingDeliveryMethod === "packstation"}
+                  className={`flex-1 py-3 text-body-sm font-bold border-l border-border transition-colors ${shippingDeliveryMethod === "packstation" ? "bg-brand text-text-primary" : "text-text-muted hover:text-text-primary"}`}
+                >
+                  Packstation
+                </button>
+              </div>
+            </div>
+
+            {shippingDeliveryMethod === "address" ? (
+              <Field
+                label="Straße und Hausnummer"
+                name="shippingStreet"
+                type="text"
+                defaultValue={profile.shippingStreet ?? ""}
+                required
+                wrapperClassName="w-full"
+              />
+            ) : (
+              <div className="flex flex-col sm:flex-row gap-4 w-full">
+                <Field
+                  label="Packstationnummer"
+                  name="shippingPackstationNumber"
+                  type="text"
+                  defaultValue={profile.shippingPackstationNumber ?? ""}
+                  required
+                />
+                <Field label="Postnummer" name="shippingPostNumber" type="text" defaultValue={profile.shippingPostNumber ?? ""} required />
+              </div>
+            )}
+
+            <div className="flex flex-col sm:flex-row gap-4 w-full">
+              <Field label="PLZ" name="shippingZip" type="text" defaultValue={profile.shippingZip ?? ""} required />
+              <Field label="Ort" name="shippingCity" type="text" defaultValue={profile.shippingCity ?? ""} required />
+            </div>
+
+            <label className="flex flex-col gap-2 items-start w-full sm:w-1/2">
+              <span className="text-label text-text-muted">Land</span>
+              <select name="shippingCountry" defaultValue={profile.shippingCountry ?? "Deutschland"} required className={`${inputClass} bg-bg-base`}>
+                {shippingCountries.map((c) => (
+                  <option key={c.name}>{c.name}</option>
+                ))}
+              </select>
+            </label>
+
+            <div className="flex flex-col sm:flex-row gap-4 w-full">
+              <Field
+                label="Kontakt-E-Mail (optional)"
+                name="shippingContactEmail"
+                type="email"
+                defaultValue={profile.shippingContactEmail ?? ""}
+              />
+              <Field
+                label="Telefonnummer (optional)"
+                name="shippingContactPhone"
+                type="tel"
+                defaultValue={profile.shippingContactPhone ?? ""}
+              />
+            </div>
+            <p className="text-label text-text-muted">Werden nur dem Versanddienstleister übergeben, z. B. für Lieferbenachrichtigungen.</p>
+          </div>
+        )}
+
         {error && <p className="text-label text-red-600">{error}</p>}
         {success && <p className="text-label text-success">Gespeichert.</p>}