feat: email+password auth with db-backed sessions

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

app/(auth)/login/page.tsx

@@ -0,0 +1,11 @@
+import { signIn } from "@/lib/actions";
+import { AuthForm } from "@/components/auth-form";
+export default function Login() {
+  return <>
+    <h1 style={{ fontFamily: "var(--qai-font-display)", fontSize: "var(--qai-text-2xl)" }}>Sign in</h1>
+    <AuthForm action={signIn} submit="Sign in" fields={[
+      { name: "email", label: "Email", type: "email", autoComplete: "email" },
+      { name: "password", label: "Password", type: "password", autoComplete: "current-password" }]} />
+    <p><a href="/signup">Create an account</a></p>
+  </>;
+}