@-menu does not show up after pasting a mention of a deleted file

Problem shortly

@-menu becomes unavailable if you paste delted file mention to the chat window.

Reproduce

Create an empty project with two files:

  • file1.ts
  • file2.ts

The files are empty, this does not affect anything.

Open new agentic chat and type (manually, please) this:

Simple text with  @file1.ts mention 

@file2.ts mention

Than without sending the message delete file2.ts.

Go to the chat textarea, select all, copy the message. Start new chat and paste the message as it is.

It looks like file1.ts AND file2.ts exist. Ok, fine. Now put cursor between the lines and try to mention something via @ symbol. Menu does not work. And the only way to make it works - is start a new chat.

Video: Dropover Cloud Upload (the link is valid until 9 July)

You can see at the end that the menu does not work in the middle of the message.

Sys info

Version: 0.46.11
VSCode Version: 1.96.2
Commit: ae378be9dc2f5f1a6a1a220c6e25f9f03c8d4e10
Date: 2025-03-07T06:43:50.208Z
Electron: 32.2.6
Chromium: 128.0.6613.186
Node.js: 20.18.1
V8: 12.8.374.38-electron.0
OS: Darwin arm64 24.3.0