move cursor from terminal panel to main.k, button about kusion on the right click disappears

## Bug Report

Please answer these questions before submitting your issue. Thanks!

### 1. Minimal reproduce step (Required)


### 2. What did you expect to see? (Required)

We should see the kusion buttons whenever right-clicking on the main.k of a stack

### 3. What did you see instead (Required)

after opening or closing windows in terminal panel, the kusion buttons on right-clicking disappears.

### 4. What is your KusionStack components version? (Required)

no matter

Reproduce the issue in VS Code by opening main.k, moving focus between the terminal panel and the editor, and right-clicking the file. Trace the extension behavior associated with the Kusion context-menu buttons; done means those buttons remain available after terminal windows are opened or closed.

Written by the indexing model from the issue text.