Complete apartment form validation flow (#46)

frontend/e2e/app.spec.ts

@@ -259,6 +259,65 @@ test('keeps apartment add and edit workflows usable', async ({ page }) => {
 	await expectNoHorizontalOverflow(page);
 });
 
+test('keeps private-area validation focused and clears the structured server error on correction', async ({
+	page,
+}) => {
+	const apartments: object[] = [];
+	let createAttempts = 0;
+
+	await mockUser(page, true);
+	await page.route('**/api/apartments', async (route) => {
+		if (route.request().method() === 'GET') {
+			await route.fulfill({ contentType: 'application/json', json: apartments });
+			return;
+		}
+
+		createAttempts += 1;
+		if (createAttempts === 1) {
+			await route.fulfill({
+				status: 400,
+				contentType: 'application/json',
+				json: {
+					code: 'validation_failed',
+					errors: [{ field: 'privateAreas[0].label', code: 'not_blank' }],
+				},
+			});
+			return;
+		}
+
+		const apartment = { id: 'apt-private-area', ...route.request().postDataJSON() };
+		apartments.push(apartment);
+		await route.fulfill({ contentType: 'application/json', json: apartment });
+	});
+
+	await page.goto('/');
+	await page
+		.getByTestId('primary-navigation')
+		.getByRole('button', { name: 'Appartements' })
+		.click();
+	await page.locator('.page-heading > .primary-action').click();
+	await page.getByLabel("Nom de l'appartement").fill('Studio Croix-Rousse');
+	await page.getByLabel('Adresse complète').fill('8 montée de la Boucle, Lyon');
+	await page.getByLabel("Prix d'acquisition").fill('125000');
+	await page.getByRole('button', { name: 'Ajouter un espace' }).click();
+
+	const label = page.getByLabel('Libellé');
+	await page.getByRole('button', { name: 'Enregistrer' }).click();
+	await expect(page.getByText('Renseignez le libellé de chaque espace privatif.')).toBeVisible();
+	await expect(label).toBeFocused();
+	expect(createAttempts).toBe(0);
+
+	await label.fill('Chambre');
+	await page.getByRole('button', { name: 'Enregistrer' }).click();
+	await expect(page.getByText('Le libellé est obligatoire.')).toBeVisible();
+
+	await label.fill('Chambre 1');
+	await expect(page.getByText('Le libellé est obligatoire.')).toBeHidden();
+	await page.getByRole('button', { name: 'Enregistrer' }).click();
+	await expect(page.getByRole('heading', { name: 'Studio Croix-Rousse' })).toBeVisible();
+	expect(createAttempts).toBe(2);
+});
+
 test('keeps the secured API check and logout available', async ({ page }) => {
 	let logoutMethod = '';
 	await mockUser(page, true);