fix: raise text-ink/50 contrast to WCAG AA across 8 files

Live Lighthouse audit of /konto found the same class of bug as the
prior checkout/cart commit, one shade lighter: text-ink/50 measures
3.08:1 against the cream background, under the 4.5:1 WCAG AA minimum
for normal-size text. Grepped for every other use of the same token
(login divider, language switcher, sold-out label, admin image-upload
status text, admin hint text) and bumped them all to text-ink/70
(5.61:1, same value used in the earlier checkout fix) for one
consistent, compliant muted-text shade. Verified: tsc clean, 151/151
tests pass, /konto Lighthouse accessibility 96 -> 100.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

src/app/konto/page.tsx

@@ -81,7 +81,7 @@ export default async function KontoPage(props: PageProps<"/konto">) {
             </form>
           </div>
 
-          <div className="mt-10 flex items-center gap-4 text-xs text-ink/50">
+          <div className="mt-10 flex items-center gap-4 text-xs text-ink/70">
             <span className="h-px flex-1 bg-ink/10" />
             {t.account.ssoDivider}
             <span className="h-px flex-1 bg-ink/10" />