Fix topic icon picker placement

tests/ui.e2e.ts

@@ -891,6 +891,24 @@ test('inbox, archive and administration stay concise', async ({ page }) => {
 	]);
 	expect(boxes[0]?.y).toBe(boxes[1]?.y);
 	expect(boxes[1]?.y).toBe(boxes[2]?.y);
+
+	const topicIconPicker = page.locator('.topic-management-panel .taxonomy-form .icon-picker');
+	for (const width of [1280, 960, 390]) {
+		await page.setViewportSize({ width, height: 900 });
+		await topicIconPicker.getByText('Icon auswählen', { exact: true }).click();
+		const popover = topicIconPicker.locator('.icon-picker-popover');
+		await expect(popover).toBeVisible();
+		const popoverBox = await popover.boundingBox();
+		expect(popoverBox?.x ?? -1).toBeGreaterThanOrEqual(0);
+		expect((popoverBox?.x ?? width) + (popoverBox?.width ?? 1)).toBeLessThanOrEqual(width);
+		await topicIconPicker.getByText('Icon auswählen', { exact: true }).click();
+	}
+
+	await page.setViewportSize({ width: 1280, height: 900 });
+	await topicIconPicker.getByText('Icon auswählen', { exact: true }).click();
+	await topicIconPicker.getByPlaceholder('Icon suchen').fill('Satellite Dish');
+	await topicIconPicker.getByRole('button', { name: 'Satellite Dish', exact: true }).click();
+	await expect(topicIconPicker.locator('input[type="hidden"]')).toHaveValue('satellite-dish');
 });
 
 test('tools stay editable in pieces after catalog deactivation', async ({ page }, testInfo) => {