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/anki-integration.ts

@@ -461,6 +461,7 @@ export class AnkiIntegration {
       getDeck: () => this.config.deck,
       findNotes: async (query, options) =>
         (await this.client.findNotes(query, options)) as number[],
+      notifyUnavailable: (message) => this.showStatusNotification(message),
       logInfo: (message, ...args) => log.info(message, ...args),
       logWarn: (message, ...args) => log.warn(message, ...args),
       logError: (message, ...args) => log.error(message, ...args),