fix: implement fetch generation counter to handle concurrent refreshes in ScrollingList

- Added a fetch generation counter to the fetchItems method to discard stale results from concurrent fetches.
- Updated the loading state management to ensure it only updates if the fetch is the latest.
- Enhanced the refresh method to prevent stale data from being rendered when multiple refreshes occur.
- Added a test case to verify that stale fetches are discarded correctly when concurrent refreshes happen.
- Fixed CSS for mobile banners to prevent overflow and adjusted font sizes for better visibility.
- Resolved issues with task icons disappearing when extending time on overdue chores by ensuring only one fetch is active at a time.

frontend/vue-app/e2e/mode_parent/task-assignment/reward-assignment.spec.ts

@@ -62,7 +62,7 @@ test.describe('Reward assignment', () => {
     await expect(page.getByRole('button', { name: 'Assign Rewards' })).toBeVisible()
 
     await page.getByRole('button', { name: 'Assign Rewards' }).click()
-    await page.waitForURL(new RegExp(`/parent/${childId}/assign-rewards$`))
+    await page.waitForURL(new RegExp(`/parent/${childId}/assign-rewards(\\?|$)`))
 
     await expect(page.getByRole('heading', { name: 'Assign Rewards' })).toBeVisible()
 
@@ -81,7 +81,7 @@ test.describe('Reward assignment', () => {
   }) => {
     await page.goto(`/parent/${childId}`)
     await page.getByRole('button', { name: 'Assign Rewards' }).click()
-    await page.waitForURL(new RegExp(`/parent/${childId}/assign-rewards$`))
+    await page.waitForURL(new RegExp(`/parent/${childId}/assign-rewards(\\?|$)`))
     await expect(page.getByRole('heading', { name: 'Assign Rewards' })).toBeVisible()
 
     // Select two rewards
@@ -124,7 +124,7 @@ test.describe('Reward assignment', () => {
   test('Uncheck all rewards and submit — items are removed from ParentView', async ({ page }) => {
     await page.goto(`/parent/${childId}`)
     await page.getByRole('button', { name: 'Assign Rewards' }).click()
-    await page.waitForURL(new RegExp(`/parent/${childId}/assign-rewards$`))
+    await page.waitForURL(new RegExp(`/parent/${childId}/assign-rewards(\\?|$)`))
     await expect(page.getByRole('heading', { name: 'Assign Rewards' })).toBeVisible()
 
     // Uncheck the previously assigned rewards
@@ -149,7 +149,7 @@ test.describe('Reward assignment', () => {
   test('Cancel does not persist selection changes', async ({ page }) => {
     await page.goto(`/parent/${childId}`)
     await page.getByRole('button', { name: 'Assign Rewards' }).click()
-    await page.waitForURL(new RegExp(`/parent/${childId}/assign-rewards$`))
+    await page.waitForURL(new RegExp(`/parent/${childId}/assign-rewards(\\?|$)`))
     await expect(page.getByRole('heading', { name: 'Assign Rewards' })).toBeVisible()
 
     // Check an item