Register: add confirm password field with mismatch highlight

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/pages/Register.tsx

@@ -8,6 +8,7 @@ export function Register() {
   const [email, setEmail] = useState('')
   const [pin, setPin] = useState('')
   const [password, setPassword] = useState('')
+  const [confirmPassword, setConfirmPassword] = useState('')
   const [error, setError] = useState('')
   const [loading, setLoading] = useState(false)
   const navigate = useNavigate()
@@ -33,6 +34,10 @@ export function Register() {
 
   async function submitPin(e: React.FormEvent) {
     e.preventDefault()
+    if (password !== confirmPassword) {
+      setError('Passwords do not match')
+      return
+    }
     setLoading(true)
     setError('')
     try {
@@ -110,11 +115,19 @@ export function Register() {
                   placeholder="Choose a password (min 8 characters)" required autoComplete="new-password"
                   style={input}
                 />
+                <input
+                  type="password" value={confirmPassword} onChange={e => setConfirmPassword(e.target.value)}
+                  placeholder="Confirm password" required autoComplete="new-password"
+                  style={{
+                    ...input,
+                    borderColor: confirmPassword && password !== confirmPassword ? 'var(--danger)' : undefined,
+                  }}
+                />
                 {error && <p style={{ color: 'var(--danger)', fontSize: '0.85rem', textAlign: 'center' }}>{error}</p>}
                 <button type="submit" disabled={loading} style={loading ? disabledBtn : goldBtn}>
                   {loading ? 'Creating account…' : 'Create account'}
                 </button>
-                <button type="button" onClick={() => { setStep('email'); setPin(''); setPassword(''); setError('') }}
+                <button type="button" onClick={() => { setStep('email'); setPin(''); setPassword(''); setConfirmPassword(''); setError('') }}
                   style={{ background: 'none', border: 'none', color: 'var(--text-muted)',
                     fontSize: '0.8rem', cursor: 'pointer', textDecoration: 'underline' }}>
                   Use a different email