feat: lock down registration and enforce partner-only logins

shop/app/auth/sign-up/page.tsx

@@ -1,11 +1,5 @@
-import { SignUpForm } from "@/components/sign-up-form";
+import { redirect } from "next/navigation";
 
-export default function Page() {
-  return (
-    <div className="flex min-h-svh w-full items-center justify-center p-6 md:p-10">
-      <div className="w-full max-w-sm">
-        <SignUpForm />
-      </div>
-    </div>
-  );
+export default function SignUpPage() {
+  redirect("/auth/login");
 }

shop/components/auth-button.tsx

@@ -21,9 +21,6 @@ export async function AuthButton() {
       <Button asChild size="sm" variant={"outline"}>
         <Link href="/auth/login">Sign in</Link>
       </Button>
-      <Button asChild size="sm" variant={"default"}>
-        <Link href="/auth/sign-up">Sign up</Link>
-      </Button>
     </div>
   );
 }

shop/components/login-form.tsx

@@ -83,21 +83,12 @@ export function LoginForm({
                   onChange={(e) => setPassword(e.target.value)}
                 />
               </div>
-              {error && <p className="text-sm text-red-500">{error}</p>}
-              <Button type="submit" className="w-full" disabled={isLoading}>
-                {isLoading ? "Logging in..." : "Login"}
-              </Button>
-            </div>
-            <div className="mt-4 text-center text-sm">
-              Don&apos;t have an account?{" "}
-              <Link
-                href="/auth/sign-up"
-                className="underline underline-offset-4"
-              >
-                Sign up
-              </Link>
-            </div>
-          </form>
+            {error && <p className="text-sm text-red-500">{error}</p>}
+            <Button type="submit" className="w-full" disabled={isLoading}>
+              {isLoading ? "Logging in..." : "Login"}
+            </Button>
+          </div>
+        </form>
         </CardContent>
       </Card>
     </div>

shop/lib/actions/auth.ts

@@ -5,30 +5,33 @@ import { headers } from 'next/headers'
 
 export async function signIn(email: string, password: string) {
   const supabase = await createClient()
-  const { error } = await supabase.auth.signInWithPassword({
+  const { data, error } = await supabase.auth.signInWithPassword({
     email,
     password,
   })
   if (error) {
     throw new Error(error.message)
   }
+
+  const userId = data.user?.id
+  if (userId) {
+    const { data: userData, error: userError } = await supabase
+      .from('users')
+      .select('role')
+      .eq('id', userId)
+      .single()
+
+    if (userError || !userData || (userData.role !== 'partner' && userData.role !== 'admin')) {
+      await supabase.auth.signOut()
+      throw new Error("Zugriff verweigert. Nur registrierte Partner dürfen sich anmelden.")
+    }
+  }
+
   return { success: true }
 }
 
 export async function signUp(email: string, password: string) {
-  const supabase = await createClient()
-  const origin = (await headers()).get('origin') || ''
-  const { error } = await supabase.auth.signUp({
-    email,
-    password,
-    options: {
-      emailRedirectTo: `${origin}/protected`,
-    },
-  })
-  if (error) {
-    throw new Error(error.message)
-  }
-  return { success: true }
+  throw new Error("Registrierung ist deaktiviert.")
 }
 
 export async function signOut() {