Being able to undo/redo without having to access the server.

So, I understand that you can undo/redo by using the "History" feature, but the "History" feature requires accessing the server (and hence mandates internet access), so I'm **unable to undo/redo when I have no internet or simply can't access the server**.

### What

Make it possible to undo/redo when there's no internet (like how other note/text editors have always been able to do so offline).

### Why

**It's very common that users may not have internet 100% of the time** (e.g. on a plane, taking a subway, wifi/data outage, server down, etc.), but users should always be able to undo/redo (like in almost all other note/text editors). Undo/redo is one of the most basic features, it's really frustrating **when you accidentally delete some texts but have no way to recover them**.

### How
There're a couple of approaches, either/both could be considered:

1. **Add regular undo/redo buttons**, like those you find in editors like Microsoft Word.
2. **Allow accessing the "History" feature locally** instead of having to access the server every time. The "History" data can still sync with the server when it's accessible.

Please kindly let me know if any clarification is needed.

Start by tracing the existing History feature and how it accesses the server, then inspect the editor's offline behavior. Clarify whether the scope is local undo/redo, locally accessible History, or both, and verify that recovery works without network access while the requested data can still synchronize when the server is available.

Written by the indexing model from the issue text.