style: translate all source code comments to English

German inline comments alongside English identifiers create a language
mismatch that makes the code harder to read for anyone not fluent in
German. All 28 affected comments across 14 files are now in English,
consistent with the rest of the project's written artifacts.

src/main/index.ts

@@ -9,11 +9,12 @@ import { getHlsCacheEnabled } from './prefs/hlsCachePref'
 
 const isDev = !app.isPackaged
 
-// Erlaubt video.play() ohne vorangehende User-Geste (nötig, weil play() in hls.js-Callbacks
-// aufgerufen wird, die asynchron weit nach dem ursprünglichen Click-Event stattfinden).
+// Allows video.play() without a prior user gesture — play() is called from hls.js callbacks
+// that fire asynchronously long after the original click event.
 app.commandLine.appendSwitch('autoplay-policy', 'no-user-gesture-required')
-// Explizite Cache-Größe verhindert Chromiums dynamische Größenberechnung, die bei
-// wechselndem freiem Speicherplatz zu "Invalid cache (current) size"-Fehlern führt.
+// Explicit cache size prevents Chromium's dynamic sizing, which causes "Invalid cache (current)
+// size" errors when available disk space fluctuates.
+
 app.commandLine.appendSwitch('disk-cache-size', String(500 * 1024 * 1024))
 
 function createWindow(): BrowserWindow {