feat: upgrade toolchain and soften sync recovery after network blips

Bump Vite 8, matrix-js-sdk, and related deps; fix immer/vanilla-extract imports for new majors. Replace blocking sync error dialog with background recovery on wake/offline, and disable Vite auto-open in dev. Add feature handoff documentation index.

src/app/utils/animatedStickerConverter.ts

@@ -1,7 +1,7 @@
 // eslint-disable-next-line import/no-extraneous-dependencies
 import lottie from 'lottie-web/build/player/lottie_light';
 // eslint-disable-next-line import/no-extraneous-dependencies
-import pako from 'pako';
+import { inflate } from 'pako';
 // eslint-disable-next-line import/no-extraneous-dependencies
 import GIF from 'gif.js';
 
@@ -26,7 +26,7 @@ const TRANSPARENT_COLOR = 0xFF00FF;
  * @returns The Lottie animation JSON object
  */
 function decompressTgs(tgsData: ArrayBuffer): object {
-  const decompressed = pako.inflate(new Uint8Array(tgsData), { to: 'string' });
+  const decompressed = inflate(new Uint8Array(tgsData), { to: 'string' });
   return JSON.parse(decompressed);
 }