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

frontend/app/inventory/InventoryEditForm.tsx

@@ -1,7 +1,7 @@
 'use client';
 
-import { useState, useTransition } from 'react';
-import { updateInventoryItem } from './actions';
+import { useState } from 'react';
+import { useRouter } from 'next/navigation';
 import type { InventoryItem } from '../../features/inventory/types';
 import { UNIT_OPTIONS } from '../../lib/units';
 
@@ -46,8 +46,9 @@ const LOCATION_OPTIONS = [
 
 export default function InventoryEditForm({ item }: Props) {
   const [isEditing, setIsEditing] = useState(false);
-  const [isPending, startTransition] = useTransition();
+  const [isPending, setIsPending] = useState(false);
   const [error, setError] = useState<string | null>(null);
+  const router = useRouter();
 
   if (!isEditing) {
     return (
@@ -79,16 +80,35 @@ export default function InventoryEditForm({ item }: Props) {
           const raw = formData.get('quantity') as string;
           const unit = formData.get('unit') as string;
           const { quantity, unit: parsedUnit } = parseQuantityInput(raw, unit);
-          formData.set('quantity', String(quantity));
-          formData.set('unit', parsedUnit);
-          startTransition(async () => {
-            try {
-              await updateInventoryItem(formData);
-              setIsEditing(false);
-            } catch (err) {
-              setError(err instanceof Error ? err.message : 'Okänt fel');
+
+          const payload: Record<string, unknown> = { opened: formData.get('opened') === 'on' };
+          if (raw) payload.quantity = quantity;
+          if (parsedUnit) payload.unit = parsedUnit;
+          payload.location = String(formData.get('location') || '').trim();
+          payload.brand = String(formData.get('brand') || '').trim();
+          payload.suitableFor = String(formData.get('suitableFor') || '').trim();
+          payload.comment = String(formData.get('comment') || '').trim();
+          const bestBeforeDate = String(formData.get('bestBeforeDate') || '').trim();
+          payload.bestBeforeDate = bestBeforeDate || null;
+
+          setIsPending(true);
+          try {
+            const res = await fetch(`/api/admin/inventory-item/${item.id}`, {
+              method: 'PATCH',
+              headers: { 'Content-Type': 'application/json' },
+              body: JSON.stringify(payload),
+            });
+            if (!res.ok) {
+              const data = await res.json().catch(() => ({}));
+              throw new Error(data?.error || 'Kunde inte uppdatera');
             }
-          });
+            setIsEditing(false);
+            router.refresh();
+          } catch (err) {
+            setError(err instanceof Error ? err.message : 'Okänt fel');
+          } finally {
+            setIsPending(false);
+          }
         }}
         style={{
           display: 'grid',