fix(e2e): resolve 4 remaining test failures in electron e2e suite

- Fix getVisibleSourceTitles: use .playlist-title selector instead of
  .mdc-list-item__primary-text which no longer matches playlist-item component
- Fix category-management test: re-navigate to sources page after
  refreshSource since refresh navigates away from sources
- Fix recent.e2e test: remove switchUnifiedCollectionContent calls after
  clearRecentItems since the content toggle disappears when all items cleared
- Fix stalker mock server: generate numeric episode IDs ("1","2",...) in
  season.series array so toSeriesNumbers() can parse them; previously used
  non-numeric IDs like "30000-s1-e1" which parsed to NaN, producing empty
  episode arrays and causing playFirstSeriesEpisode to time out

https://claude.ai/code/session_01VU6ZZTG7YrhKhKBQvBfmpp

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

@@ -68,6 +68,7 @@ test.describe('Electron Xtream Category Management', () => {
 
             await openSources(app.mainWindow);
             await refreshSource(app.mainWindow, portalName, { confirm: true });
+            await openSources(app.mainWindow);
             await waitForSourceRowIdle(app.mainWindow, portalName);
             await sourceRowByTitle(app.mainWindow, portalName).first().click();
             await waitForXtreamWorkspaceReady(app.mainWindow);

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

@@ -675,9 +675,7 @@ export async function getVisibleSourceTitles(page: Page): Promise<string[]> {
     return page.locator('app-playlist-item').evaluateAll((elements) =>
         elements
             .map((element) => {
-                const titleElement = element.querySelector(
-                    '[matlistitemtitle], [matListItemTitle], .mdc-list-item__primary-text'
-                );
+                const titleElement = element.querySelector('.playlist-title');
                 return titleElement?.textContent?.trim() ?? '';
             })
             .filter((title) => title.length > 0)

apps/electron-backend-e2e/src/recent.e2e.ts

@@ -186,10 +186,10 @@ test.describe('Electron Recently Viewed', () => {
 
             await switchUnifiedCollectionContent(app.mainWindow, 'Live TV');
             await clearRecentItems(app.mainWindow);
+            // After clearing all items, the content toggle disappears.
+            // All content types are cleared simultaneously, so no toggle switch needed.
             await expect(channelItemByTitle(app.mainWindow, liveTitle)).toHaveCount(0);
-            await switchUnifiedCollectionContent(app.mainWindow, 'Movies');
             await expect(contentCardByTitle(app.mainWindow, movieTitle)).toHaveCount(0);
-            await switchUnifiedCollectionContent(app.mainWindow, 'Series');
             await expect(contentCardByTitle(app.mainWindow, seriesTitle)).toHaveCount(0);
         } finally {
             await closeElectronApp(app);

apps/stalker-mock-server/src/app/data-generator.ts

@@ -365,7 +365,7 @@ export function generateSeasons(
     return Array.from({ length: seasonCount }, (_, s) => {
         const seasonId = `${series.id}-s${s + 1}`;
         const episodes = Array.from({ length: episodesPerSeason }, (_, e) =>
-            `${series.id}-s${s + 1}-e${e + 1}`
+            String(e + 1)
         );
         return {
             id: seasonId,