fix(sources): keep deletes busy until settled and on screen; refresh E2E via the switcher

PR #1932 round 1 (CI + local Codex/Greptile on the bot fixes):

- CI: category-management.e2e refreshed the active playlist through the
  old switcher trigger's inline refresh button, which the redesign
  replaced with the switcher row menu (⋯ → Refresh playlist). The helper
  now goes through that menu; it failed on all three OS shards.
- A desktop Xtream delete's completed event cleared its progress while
  PlaylistsService still cleaned up (parental lock, stored state), so the
  already-deleted source was actionable again on Sources and back in the
  switcher until the store dropped it. A terminal event now only ends
  Cancel; the row stays busy until the delete settles and the removal
  service clears it.
- A running delete (from the switcher, say) disappeared from Sources when
  the page's saved filters excluded it, hiding its only progress and
  Cancel. Running deletes stay listed whatever the filters.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

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

@@ -545,8 +545,15 @@ async function expectCategoryCentered(row: Locator): Promise<void> {
 }
 
 async function refreshFromWorkspaceHeader(page: Page): Promise<void> {
+    // Refresh for the active source lives in its switcher row menu.
+    await page.getByTestId('playlist-switcher-trigger').click();
     await page
-        .getByRole('button', { name: 'Refresh playlist', exact: true })
+        .locator(
+            'app-playlist-switcher-panel [role="option"][aria-current="true"] .source-row__more'
+        )
+        .click();
+    await page
+        .getByRole('menuitem', { name: 'Refresh playlist', exact: true })
         .click();
 
     const dialog = page.locator('mat-dialog-container');