fix: make category slug optional

backend/src/controllers/healthCheck.controller.js

@@ -28,7 +28,7 @@ export const createCategory = async (req, res) => {
 		const category = await prisma.healthCheckCategory.create({
 			data: {
 				name,
-				slug,
+				slug: slug || null,
 				description,
 				isActive: isActive ?? true,
 				sortOrder: sortOrder ? Number(sortOrder) : 1000,
@@ -58,6 +58,8 @@ export const updateCategory = async (req, res) => {
 
 		if (data.sortOrder !== undefined) data.sortOrder = Number(data.sortOrder);
 
+		if (data.slug === "") data.slug = null;
+
 		const updatedCategory = await prisma.$transaction(async (tx) => {
 			const category = await tx.healthCheckCategory.update({
 				where: { id: Number(id) },