feat(switcher): rebuild the playlist switcher as an overlay popover

The switcher's mat-menu becomes a CDK connected overlay
(app-playlist-switcher-panel), 440px wide, with a dimmed, blurred
backdrop; only its list scrolls and row menus open above it.

- Header with the source count, Add playlist and All sources.
- Search by name or host, autofocused; the type filter is one segmented
  control (All / M3U / Xtream / Stalker with counts) instead of three
  checkboxes, remembered between openings (the old checkbox setting is
  migrated). The search is no longer kept between openings.
- "Recent" (the three most recently opened, kept across restarts) above
  "All" in the Sources page order, as compact source rows: the current
  one tinted with a check. Each row's ⋯ menu holds Refresh, Playlist
  info, Account info, Check again and Remove (with Undo); the footer's
  info, account and add actions moved there and to the header.
- Keyboard: a listbox driven by aria-activedescendant from the search
  field. Arrow keys move and wrap, Enter opens, Shift+F10 opens the
  row's menu, Escape closes and returns focus to the trigger. Hints in
  the footer.
- Deleting from a row menu moves focus to the toast's Undo, since the
  row (and its focus) left the page.

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

apps/web-e2e/src/xtream.e2e.ts

@@ -61,18 +61,15 @@ async function openPlaylistDetailsDialog(page: Page, title: string) {
         await playlistSettingsButton.click();
     } else {
         await page
-            .locator('app-playlist-switcher .playlist-switcher-trigger')
+            .locator('[data-test-id="playlist-switcher-trigger"]')
             .click();
 
-        const switcherMenu = page.getByRole('menu').filter({ hasText: title });
-        const sourceRow = switcherMenu
-            .locator('.playlist-item')
+        const sourceRow = page
+            .locator('app-playlist-switcher-panel [role="option"]')
             .filter({ hasText: title })
             .first();
         await expect(sourceRow).toBeVisible();
-        await sourceRow
-            .getByRole('button', { name: 'Playlist actions' })
-            .click();
+        await sourceRow.locator('.source-row__more').click();
         await page.getByRole('menuitem', { name: 'Playlist info' }).click();
     }