the way back off the sign-in wall is a place a thumb can land

"What is this?" was 342 wide and 15 tall. It is the only escape from a sign-in
screen for someone who arrived not knowing what Tabs is, so it reaches 44 like
the button above it. Same property the footer links just got, same reason.

Measured on the live page at 390: no overflow, no contrast failure, and
"Continue with Hanzo" was already 342x44 — this was the one thing short.

app/app/page.tsx

@@ -197,7 +197,12 @@ export default function App() {
           {busy ? 'Taking you to hanzo.id…' : 'Continue with Hanzo'}
         </button>
         {error ? <p className="mt-3 text-xs text-amber-500">{error}</p> : null}
-        <Link href="/" className="mt-6 text-xs text-[var(--text-disabled)] hover:text-muted-foreground">
+        {/* The way back off a sign-in wall is the one link that must be easy to hit,
+            so it reaches 44px like the button above it. Its text alone is 15 tall. */}
+        <Link
+          href="/"
+          className="mt-4 inline-flex min-h-11 items-center text-xs text-[var(--text-disabled)] hover:text-muted-foreground"
+        >
           ← What is this?
         </Link>
       </main>