Canvas extension issue when using built-in app zoom

### Short summary

Canvas extension offset issue when using built-in app zoom

### Affected version or release

v1.0.24

### Installation context

App installed on MacOS 15.7.7

### What happened?

When a canvas extension is loaded, any zoom change other than default render the app unusable due to the webview of the canvas extension not applying the zoom and getting offset inside the GH app window, see:

### Steps to reproduce

1. Load any canvas extension using the webview
2. zoom in/out in the app using ctrl +/-

### Expected behavior

- canvas extension is also affected by the zoom, and follows the layout as expected

### Additional context

_No response_

在 macOS 15.7.7 上使用 v1.0.24，通过在 webview 中加载 canvas 扩展并使用 Ctrl+/- 更改应用缩放来复现该问题。检查 canvas 扩展 webview 对缩放和布局的处理；当该扩展能够跟随应用缩放，且不会发生偏移或变得无法使用时，即表示完成。

由索引模型根据 Issue 内容生成。