message: Clarify current state of cross-signing private keys
diff: @@ -221,8 +221,14 @@ class MatrixClientPeg {
  };
  if (SettingsStore.isFeatureEnabled("feature_cross_signing")) {
  - // TODO: Cross-signing keys are temporarily in memory only. A
  - // separate task in the cross-signing project will build from here.
  + // This stores the cross-signing private keys in memory for the JS SDK. They
  + // are also persisted to Secure Secret Storage in account data by
  + // the JS SDK when created.
  + // XXX: On desktop platforms, we plan to store only the SSSS default
  + // key in a secure enclave, while the cross-signing private keys
  + // will still be retrieved from SSSS, so it's unclear that we
  + // actually need these cross-signing application callbacks for Riot.
  + // Should the JS SDK default to in-memory storage of these itself?
  const keys = {};
  opts.cryptoCallbacks = {
  getCrossSigningKey: k => keys[k],
  