Autofocus email field on login and signup pages

Add the autoFocus prop to the email input on both the login and signup
views so the cursor lands in the email field on page load.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: Brian Casel

app/javascript/pages/auth/Login.tsx

@@ -48,6 +48,7 @@ export default function Login() {
               id="email"
               type="email"
               autoComplete="email"
+              autoFocus
               required
               value={form.data.email}
               onChange={(e) => form.setData("email", e.target.value)}

app/javascript/pages/auth/Signup.tsx

@@ -45,6 +45,7 @@ export default function Signup() {
               id="email"
               type="email"
               autoComplete="email"
+              autoFocus
               required
               aria-invalid={!!errors.email}
               value={form.data.email}