fix(editor): import & save logic (#15098)

fix #15080
fix #15085
fix #15031
fix #15094


#### PR Dependency Tree


* **PR #15098** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Bug Fixes**
  * Improved code-block paste behavior for plain-text insertion
  * Fixed block selection ordering to reflect document model
  * Made table cell formatting resilient to conversion errors
  * Ensured user feature list is consistently returned as an array

* **Refactor**
  * Streamlined authentication session fetch and profile enrichment flow

* **Tests**
  * Added tests for markdown blockquote list preservation
  * Added authentication session validation tests
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/common/realtime/src/index.ts

@@ -171,7 +171,7 @@ export interface CurrentUserProfileSnapshot {
   emailVerified: boolean;
   hasPassword: boolean | null;
   avatarUrl: string | null;
-  features?: string[];
+  features: string[];
 }
 
 export interface UserSettingsSnapshot {