add /login route

POSTs email + password to /auth/email/login, stores JWT, redirects
to /account (route to be added).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/routes.ts

@@ -4,4 +4,5 @@ export default [
   index('routes/_index.tsx'),
   route('signup', 'routes/signup.tsx'),
   route('verify', 'routes/verify.tsx'),
+  route('login', 'routes/login.tsx'),
 ] satisfies RouteConfig;