feat(api): implement new API routes for bulk category updates, inventory consumption, and product management with authentication

frontend/app/baslager/AddToPantryForm.tsx

@@ -1,8 +1,8 @@
 'use client';
 
-import { useState, useTransition } from 'react';
+import { useState } from 'react';
+import { useRouter } from 'next/navigation';
 import type { Product } from '../../features/inventory/types';
-import { addPantryItem } from './actions';
 
 type Props = {
   products: Product[];
@@ -11,23 +11,34 @@ type Props = {
 
 export default function AddToPantryForm({ products, pantryProductIds }: Props) {
   const [selectedId, setSelectedId] = useState('');
-  const [isPending, startTransition] = useTransition();
+  const [isPending, setIsPending] = useState(false);
   const [error, setError] = useState<string | null>(null);
+  const router = useRouter();
 
   const available = products.filter((p) => !pantryProductIds.has(p.id));
 
-  function handleSubmit(e: React.FormEvent) {
+  async function handleSubmit(e: React.FormEvent) {
     e.preventDefault();
     if (!selectedId) return;
     setError(null);
-    startTransition(async () => {
-      try {
-        await addPantryItem(Number(selectedId));
-        setSelectedId('');
-      } catch (err) {
-        setError(err instanceof Error ? err.message : 'Okänt fel');
+    setIsPending(true);
+    try {
+      const res = await fetch('/api/admin/pantry-item', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ productId: Number(selectedId) }),
+      });
+      if (!res.ok) {
+        const data = await res.json().catch(() => ({}));
+        throw new Error(data?.error || 'Kunde inte lägga till');
       }
-    });
+      setSelectedId('');
+      router.refresh();
+    } catch (err) {
+      setError(err instanceof Error ? err.message : 'Okänt fel');
+    } finally {
+      setIsPending(false);
+    }
   }
 
   return (