fix(anki,appimage): handle proxy port conflicts and stray GPU child

- AnkiConnect proxy now detects EADDRINUSE, logs a warning, and surfaces an overlay notification instead of crashing video startup
- Background AppImage bootstrap runs Chromium with in-process-gpu so no GPU child survives app.exit() and outlives the FUSE mount, fixing the remaining DrKonqi "Service Crash" case
- Add changelog fragment for the proxy fix; update the AppImage quit fragment with the GPU child root cause

src/main-entry-runtime.ts

@@ -35,6 +35,10 @@ type EarlyAppLike = {
   setPath: (name: 'userData', value: string) => void;
 };
 
+type BackgroundBootstrapAppLike = {
+  exit: (code: number) => void;
+};
+
 type CommandLineLike = {
   appendSwitch: (name: string, value?: string) => void;
 };
@@ -132,6 +136,22 @@ export function applyEarlyLinuxCommandLineSwitches(
   );
 }
 
+// The detach bootstrap exits within milliseconds, but a separate GPU child it
+// spawned survives app.exit() and keeps executing from the bootstrap's FUSE
+// mount until session teardown finally unmaps it — SIGBUS, surfaced by DrKonqi
+// as a "Service Crash" notification on every video close. Keeping the GPU
+// in-process means the bootstrap leaves no child behind.
+export function applyBackgroundBootstrapCommandLineSwitches(
+  commandLine: CommandLineLike,
+  argv: string[],
+  env: NodeJS.ProcessEnv,
+  platform: NodeJS.Platform = process.platform,
+): void {
+  if (platform !== 'linux') return;
+  if (!shouldDetachBackgroundLaunch(argv, env)) return;
+  commandLine.appendSwitch('in-process-gpu');
+}
+
 function consumesLaunchMpvValue(token: string): boolean {
   return (
     token.startsWith('--') &&
@@ -241,6 +261,10 @@ export function shouldDetachBackgroundLaunch(argv: string[], env: NodeJS.Process
   return true;
 }
 
+export function exitBackgroundBootstrap(app: BackgroundBootstrapAppLike): void {
+  app.exit(0);
+}
+
 export function shouldHandleHelpOnlyAtEntry(argv: string[], env: NodeJS.ProcessEnv): boolean {
   if (env.ELECTRON_RUN_AS_NODE === '1') return false;
   const args = parseCliArgs(argv);