fix(auth): dismiss the verify banner once the user acts

The verifyInvalid banner (a one-time entry notice) lingered on later screens
after the user clicked its "Send a new link" CTA and returned to sign-in.
Clear the verify state in reset(), so any deliberate action — mode switch,
CTA, or submit — dismisses it.

frontend/src/components/Welcome.tsx

@@ -321,6 +321,9 @@ function AuthCard() {
   const reset = () => {
     setError("");
     setDone("");
+    // The verify banners are a one-time entry notice — dismiss once the user takes any deliberate
+    // action (mode switch, CTA, submit) so it doesn't linger stalely on later screens.
+    setVerify(null);
   };
 
   async function onSubmit(e: React.FormEvent) {
@@ -411,7 +414,7 @@ function AuthCard() {
           {t("welcome.auth.verifyInvalid")}{" "}
           <button
             onClick={() => {
-              reset();
+              reset(); // also clears the verify banner (see reset())
               setMode("resend");
             }}
             className="font-semibold text-accent hover:underline"