Email confirmation, change email/password, show/hide passwords

- Sign-up emails a confirmation link (24h); unconfirmed accounts see a
  banner on the web with "send it again", and status in Settings.
- Change email (needs the password): the new address gets a confirmation
  link and only replaces the old one once clicked; the old address gets a
  heads-up with a reset-password link. Pending changes can be cancelled.
- Change password (needs the current one): signs out other sessions.
- Password fields have Show/Hide on web and mobile.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MzFywujuH9TiuXbr9vjoX8

apps/web/src/components/Nav.tsx

@@ -2,7 +2,8 @@
 
 import Link from 'next/link';
 import { useRouter } from 'next/navigation';
-import { api, useMe } from '@/lib/api';
+import { useState } from 'react';
+import { api, client, useMe } from '@/lib/api';
 import { SupportLink } from './SupportLink';
 
 export function Nav() {
@@ -14,6 +15,7 @@ export function Nav() {
     router.push('/');
   };
   return (
+    <>
     <nav className="nav">
       <Link href="/" className="brand">
         <img className="brand-logo" src="/logo.png" alt="" width={30} height={30} />
@@ -41,5 +43,26 @@ export function Nav() {
         )}
       </div>
     </nav>
+    {me && !me.emailVerified && <VerifyBanner email={me.pendingEmail ?? me.email} />}
+    </>
+  );
+}
+
+/** Until they confirm, a forgotten password can't be reset; nudge them. */
+function VerifyBanner({ email }: { email: string }) {
+  const [sent, setSent] = useState(false);
+  const resend = async () => {
+    try {
+      await client.resendVerification();
+      setSent(true);
+    } catch (err) {
+      alert((err as Error).message);
+    }
+  };
+  return (
+    <div className="banner">
+      Confirm your email: we sent a link to <strong>{email}</strong>.{' '}
+      {sent ? <span className="muted">Sent again.</span> : <button className="link-button" onClick={resend}>Send it again</button>}
+    </div>
   );
 }