style: translate all remaining German code comments to English

German comments had survived the earlier translation pass. Mixing
languages in comments creates inconsistency and makes the codebase
harder to read for non-German contributors.

src/main/index.ts

@@ -64,15 +64,15 @@ function createWindow(): BrowserWindow {
 }
 
 /**
- * CORS-Bypass für Twitch CDN und HLS-Streams.
- * hls.js im Renderer sendet Requests von localhost/file:// — Twitch CDN erwartet
- * Origin: https://www.twitch.tv. Wir setzen Origin + Referer auf ausgehenden Requests
- * und ergänzen CORS-Response-Header, damit Chromium die Antworten akzeptiert.
+ * CORS bypass for Twitch CDN and HLS streams.
+ * hls.js in the renderer sends requests from localhost/file:// — Twitch CDN expects
+ * Origin: https://www.twitch.tv. We set Origin + Referer on outgoing requests
+ * and inject CORS response headers so Chromium accepts the responses.
  *
- * HLS-Cache-Unterdrückung: xhrSetup in hls.js setzt Cache-Control: no-store auf jedem
- * XHR. Das löst einen CORS-Preflight aus (Cache-Control ist kein safelisted header).
- * Damit der Preflight durchkommt, muss onHeadersReceived auch ttvnw.net-Domains abdecken
- * (Segment-CDN: *.j.cloudfront.hls.ttvnw.net — enthält nicht "cloudfront.net").
+ * HLS cache suppression: xhrSetup in hls.js sets Cache-Control: no-store on every
+ * XHR. This triggers a CORS preflight (Cache-Control is not a safelisted header).
+ * For the preflight to pass, onHeadersReceived must also cover ttvnw.net domains
+ * (segment CDN: *.j.cloudfront.hls.ttvnw.net — does not contain "cloudfront.net").
  */
 function setupTwitchCors(): void {
   const isTwitchCdn = (url: string): boolean =>