Matches the Figma mockup (checkmark hero, order summary card,
delivery-status panel, testimonial band) with the checkout's 4-step
bar inserted (all steps done) and the "Bis dahin: Lass dich
inspirieren" block omitted, per request.
Extracted the step bar into a shared CheckoutSteps component so
/checkout and /bestellbestaetigung don't duplicate it. The actually-
selected shipping cost and payment method are captured into a
sessionStorage snapshot by /checkout's "Jetzt kaufen" click (there's
no real order backend, so this click is what "placing the order"
means here) and read back on the confirmation page — not just
defaulted to the first active method of each, so the receipt matches
what the shopper actually picked. Also tightened the checkout
newsletter-consent copy ("Wenn du zustimmst" instead of "Wenn du
oben zustimmst").
Marco