fix: upgrade matrix-js-sdk 38.2.0 -> 41.5.0 with API compat fixes

- sessionMembershipsForRoom() removed in v41 (was synchronous, static)
- Replacement: read session.memberships directly (always up-to-date, sync)
  - useCall.ts: useCallMembers reads session.memberships
  - useCallEmbed.ts: createCallEmbed reads rtcSession.memberships
  - CallEmbedProvider.tsx: inline check on session.memberships
- Remove unused MatrixRTCSession import from CallEmbedProvider
- clearLoginData: also unregisters service workers and clears SW caches

package.json

@@ -101,7 +101,7 @@
     "linkify-react": "4.3.3",
     "linkifyjs": "4.3.3",
     "lodash": "4.18.1",
-    "matrix-js-sdk": "38.2.0",
+    "matrix-js-sdk": "41.5.0",
     "matrix-widget-api": "1.17.0",
     "millify": "6.1.0",
     "pdfjs-dist": "5.7.284",