Deactivated product shows as sold out, StepArrow to black, newsletter checkmarks fixed

- /todo-cards's detail page (the only page resolving a product regardless
  of active status) now renders both CTAs as "Ausverkauft" and disabled
  when the product is deactivated, instead of fully buyable — variants are
  dropped too, since AddToCartButton's outOfStock prop is otherwise ignored
  whenever variants is non-empty.
- StepArrow: brand orange didn't fit here after all, switched to
  near-black (#222221) per feedback.
- Newsletter/"Impulse & Tipps" checklist checkmarks (WeeklyImpulsesHero.tsx,
  WeeklyBenefits.tsx) were still the old un-recolorable icon-check.svg —
  same inline-SVG orange-checkmark fix as todo-cards/Challenge, plus
  items-start instead of items-center on WeeklyImpulsesHero's list for
  top-alignment consistency.

app/newsletter/components/WeeklyBenefits.tsx

@@ -8,6 +8,17 @@ const benefits = [
   { title: "Motivation & Erinnerung", desc: "Ein freundlicher Schub in die richtige Richtung." },
 ];
 
+// Inline, brand-orange stroke — same fix/reasoning as
+// WeeklyImpulsesHero.tsx's own IconCheck (icon-check.svg's fill can't be
+// recolored from outside the SVG when loaded via <img src>/next/image).
+function IconCheck() {
+  return (
+    <svg width="20" height="20" viewBox="0 0 20 20" fill="none" className="size-5 shrink-0 mt-0.5">
+      <path d="M4 10.5l4.5 4.5L16 5.5" stroke="#f6a701" strokeWidth="2.2" strokeLinecap="round" strokeLinejoin="round" />
+    </svg>
+  );
+}
+
 export function WeeklyBenefits() {
   return (
     <section className="w-full bg-bg-base flex flex-col lg:flex-row gap-10 lg:gap-16 items-center py-12 md:py-16 px-[var(--layout-padding-x)]">
@@ -31,7 +42,7 @@ export function WeeklyBenefits() {
         <ul className="flex flex-col gap-4 items-start w-full">
           {benefits.map((b) => (
             <li key={b.title} className="flex gap-[0.625rem] items-start w-full">
-              <Image alt="" src="/icon-check.svg" width={20} height={20} className="size-5 shrink-0 mt-0.5" />
+              <IconCheck />
               <div className="flex flex-col gap-0.5 items-start flex-1 min-w-0">
                 <p className="font-semibold text-body text-text-primary">{b.title}</p>
                 <p className="text-body-sm text-text-muted">{b.desc}</p>

app/newsletter/components/WeeklyImpulsesHero.tsx

@@ -16,6 +16,17 @@ function LockIcon() {
   );
 }
 
+// Inline, brand-orange stroke — icon-check.svg's fill lives in an internal
+// CSS var that can't be recolored from outside the SVG when loaded via
+// <img src>/next/image, same fix/reasoning as todo-cards's own IconCheck.
+function IconCheck() {
+  return (
+    <svg width="20" height="20" viewBox="0 0 20 20" fill="none" className="size-5 shrink-0 mt-0.5">
+      <path d="M4 10.5l4.5 4.5L16 5.5" stroke="#f6a701" strokeWidth="2.2" strokeLinecap="round" strokeLinejoin="round" />
+    </svg>
+  );
+}
+
 const checklist = [
   "Jeden Mittwoch neue Impulse & Tipps",
   "Kurz & knackig – in 5 Minuten gelesen",
@@ -89,8 +100,8 @@ export function WeeklyImpulsesHero() {
 
             <ul className="flex flex-col gap-3 items-start w-full">
               {checklist.map((item) => (
-                <li key={item} className="flex gap-[0.625rem] items-center w-full">
-                  <Image alt="" src="/icon-check.svg" width={20} height={20} className="size-5 shrink-0" />
+                <li key={item} className="flex gap-[0.625rem] items-start w-full">
+                  <IconCheck />
                   <span className="flex-1 text-body text-text-primary">{item}</span>
                 </li>
               ))}