fix(e2e): fix dragSourceBefore and toggleManagedCategory selectors

- dragSourceBefore: replace mat-list-item with .playlist-item as the
  drag target; playlist-item.component has no mat-list-item element,
  the inner container div carries the .playlist-item class
- toggleManagedCategory: match categories by name only instead of
  name+itemCount; after an Xtream refresh the itemCounts Map passed to
  the dialog may be empty (streams not yet counted), causing a false
  mismatch even though the category is present and uniquely named

https://claude.ai/code/session_01VU6ZZTG7YrhKhKBQvBfmpp

apps/electron-backend-e2e/src/category-management.e2e.ts

@@ -170,7 +170,7 @@ async function toggleManagedCategory(
             (await categoryRow.locator('.item-count').textContent())?.trim() ?? '';
         const itemCount = Number.parseInt(countText.replace(/[()]/g, ''), 10) || 0;
 
-        if (name !== targetCategory.name || itemCount !== targetCategory.itemCount) {
+        if (name !== targetCategory.name) {
             continue;
         }
 

apps/electron-backend-e2e/src/electron-test-fixtures.ts

@@ -707,7 +707,7 @@ export async function dragSourceBefore(
     targetTitle: string
 ): Promise<void> {
     const source = sourceRowByTitle(page, sourceTitle).locator('.drag-icon');
-    const target = sourceRowByTitle(page, targetTitle).locator('mat-list-item');
+    const target = sourceRowByTitle(page, targetTitle).locator('.playlist-item');
 
     await expect(source.first()).toBeVisible();
     await expect(target.first()).toBeVisible();