Nudge checkmark/login icon vertical alignment

- Checklist checkmarks (Challenge, todo-cards, newsletter): mt-0.5 -> mt-1,
  centering against the first line's glyphs instead of sitting flush at
  the very top edge.
- Navbar login icon: -translate-y-0.5 — its round head vs. wide shoulders
  read as optically bottom-heavy next to the cart icon despite both
  having a mathematically centered bounding box.

app/newsletter/components/WeeklyBenefits.tsx

@@ -13,7 +13,7 @@ const benefits = [
 // 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">
+    <svg width="20" height="20" viewBox="0 0 20 20" fill="none" className="size-5 shrink-0 mt-1">
       <path d="M4 10.5l4.5 4.5L16 5.5" stroke="#f6a701" strokeWidth="2.2" strokeLinecap="round" strokeLinejoin="round" />
     </svg>
   );

app/newsletter/components/WeeklyImpulsesHero.tsx

@@ -21,7 +21,7 @@ function LockIcon() {
 // <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">
+    <svg width="20" height="20" viewBox="0 0 20 20" fill="none" className="size-5 shrink-0 mt-1">
       <path d="M4 10.5l4.5 4.5L16 5.5" stroke="#f6a701" strokeWidth="2.2" strokeLinecap="round" strokeLinejoin="round" />
     </svg>
   );