Center cart's CartTrustBadges list below 640px

The previous TrustRow.tsx fix didn't touch this — the cart summary
sidebar renders its own inline trust-badge list, not the shared
TrustRow component. Each row was w-full unconditionally, so
items-center on the container was a no-op (a full-width flex child
centers to no visible effect). Now w-auto + justify-center below sm:
(icon+title as a compact centered unit), w-full + justify-start (+
flex-1 on the title) from sm: up, matching the tiered-alignment pattern
used elsewhere (Hero's social proof, TrustRow.tsx).

app/cart/components/CartContent.tsx

@@ -457,12 +457,20 @@ export function CartContent({
             </div>
 
             {/* Title only — /checkout renders the same CartTrustBadges
-                docs with description too, see CheckoutContent.tsx. */}
-            <div className="flex flex-col gap-4 items-start w-full">
+                docs with description too, see CheckoutContent.tsx.
+                Centered below sm: (640px), left-aligned from sm: up —
+                each row is w-full sm:+ only, so the icon+title sits as a
+                compact centered unit below sm: (a w-full row would make
+                items-center on the container above a no-op) and expands
+                to a left-aligned full-width row once there's more
+                horizontal room. items-start on the container gives every
+                row the same left edge once left-aligned, so nothing
+                reads staggered/crooked between rows. */}
+            <div className="flex flex-col gap-4 items-center sm:items-start w-full">
               {trustBadges.map((b) => (
-                <div key={b.id} className="flex gap-3 items-center w-full">
+                <div key={b.id} className="flex gap-3 items-center justify-center sm:justify-start w-auto sm:w-full">
                   <Image alt="" src={b.icon} width={22} height={22} className="size-[1.375rem] shrink-0 object-contain" />
-                  <span className="flex-1 text-body-sm text-text-primary">{b.title}</span>
+                  <span className="sm:flex-1 text-body-sm text-text-primary">{b.title}</span>
                 </div>
               ))}
             </div>