fix: don't state newsletter opt-in as a given before consent is checked

Both /cart's and /checkout's newsletter hint boxes phrased regular
marketing emails as an already-decided outcome ("bekommst du...").
The actual consent checkbox (unchecked by default) only exists on
/checkout's address form, and even there the copy didn't make the
outcome conditional on it. Pre-supposing opt-in like this is unlawful
under UWG/DSGVO (see the ECJ's Planet49 ruling on pre-checked consent) —
reworded both to frame it as conditional/an option, not a promise.

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

app/cart/components/CartContent.tsx

@@ -239,8 +239,15 @@ export function CartContent() {
               <div className="h-[0.1875rem] w-6 bg-brand" />
             </div>
             <div className="flex flex-col gap-2 items-start flex-1 min-w-0 text-text-primary">
+              {/* Framed as an upcoming option, not a given — the real
+                  opt-in checkbox lives on /checkout (unchecked by
+                  default), and this page doesn't show one at all, so
+                  stating regular emails as an already-decided outcome
+                  here would overstate consent that hasn't been given
+                  yet (UWG/DSGVO — pre-supposed opt-in is unlawful, same
+                  reasoning as /checkout's own newsletter hint). */}
               <p className="text-body-sm leading-[1.45]">
-                Nach deiner Bestellung bekommst du regelmäßig Impulse & Tipps per E-Mail.
+                Beim Checkout kannst du dich für unsere Impulse & Tipps per E-Mail anmelden.
               </p>
               <p className="text-body-sm leading-[1.45]">
                 Für mehr Klarheit, Fokus und Struktur – jede Woche.