Applicatie afmaken en GUI-flow herstellen

Voegt boodschappenlijsten, productbeheer, realtime synchronisatie en browsercache-updates toe. Herstelt login- en sessiegedrag en maakt database-seeding herhaalbaar.\n\nCo-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

repositories/ShoppingListRepository.js

@@ -0,0 +1,71 @@
+const db = require("../config/database");
+
+class ShoppingListRepository {
+    getByHousehold(householdId) {
+        return db.prepare(`
+            SELECT shopping_lists.*,
+                   COUNT(shopping_list_items.id) AS item_count,
+                   COALESCE(SUM(shopping_list_items.checked), 0) AS checked_count
+            FROM shopping_lists
+            LEFT JOIN shopping_list_items
+                ON shopping_list_items.list_id = shopping_lists.id
+            WHERE shopping_lists.household_id = ? AND shopping_lists.archived = 0
+            GROUP BY shopping_lists.id
+            ORDER BY shopping_lists.created_at DESC, shopping_lists.id DESC
+        `).all(householdId);
+    }
+
+    findById(id, householdId) {
+        return db.prepare(`
+            SELECT * FROM shopping_lists
+            WHERE id = ? AND household_id = ?
+        `).get(id, householdId);
+    }
+
+    getItems(listId) {
+        return db.prepare(`
+            SELECT shopping_list_items.*, products.name AS product_name,
+                   categories.name AS category_name, categories.icon AS category_icon
+            FROM shopping_list_items
+            JOIN products ON products.id = shopping_list_items.product_id
+            LEFT JOIN categories ON categories.id = products.category_id
+            WHERE shopping_list_items.list_id = ?
+            ORDER BY shopping_list_items.checked ASC,
+                     shopping_list_items.sort_order ASC,
+                     shopping_list_items.created_at ASC
+        `).all(listId);
+    }
+
+    create(householdId, name) {
+        return db.prepare(`
+            INSERT INTO shopping_lists (household_id, name) VALUES (?, ?)
+        `).run(householdId, name);
+    }
+
+    addItem(listId, productId, amount) {
+        const nextSortOrder = db.prepare(`
+            SELECT COALESCE(MAX(sort_order), -1) + 1 AS value
+            FROM shopping_list_items WHERE list_id = ?
+        `).get(listId).value;
+        return db.prepare(`
+            INSERT INTO shopping_list_items (list_id, product_id, amount, sort_order)
+            VALUES (?, ?, ?, ?)
+        `).run(listId, productId, amount, nextSortOrder);
+    }
+
+    toggleItem(listId, itemId) {
+        return db.prepare(`
+            UPDATE shopping_list_items
+            SET checked = CASE checked WHEN 0 THEN 1 ELSE 0 END
+            WHERE id = ? AND list_id = ?
+        `).run(itemId, listId);
+    }
+
+    deleteItem(listId, itemId) {
+        return db.prepare(`
+            DELETE FROM shopping_list_items WHERE id = ? AND list_id = ?
+        `).run(itemId, listId);
+    }
+}
+
+module.exports = new ShoppingListRepository();