Canvas shifts upwards when editing text

### Prerequisites

- [x] I am running the latest version of ComfyUI
- [x] I have custom nodes enabled

### What happened?

When editing a text input and the input scrolls, the whole website canvas shifts up. This makes it impossible to reach UI elements at the top while an unused area is at the bottom. While I also noticed this bug in graph view, I can't reliably reproduce it the same way.

Notice in the video after finishing pasting the text:
* The menu button is gone
* The workflow combo box is gone
* An empty area appears at the bottom of the website below the usual "Edit & Run" buttons
* Scrolling up or down doesn't allow reaching the top parts of the website

https://github.com/user-attachments/assets/f7f33d7d-74a3-4f87-8ef4-4679c32fd9f3

### Steps to Reproduce

1. Set up ComfyUI so you can use it on your phone
2. Open ComfyUI in [Firefox for Android](https://www.firefox.com/en-US/download/android/) with your URL bar set at the bottom of the screen
3. Edit a text input (`Text String (Multiline)`) in a way that makes the input scroll.
5. The website content is now shifted upward for about the height of the URL bar, making the top UI elements unreachable
6. **Workaround**: Switching workflows resets the content and fills the whole canvas again. In app view it's difficult to reach that functionality though. Rotating your phone might be helpful to switch to a different workflow

### How is this affecting you?

Visual/UI issue only

### ComfyUI Frontend Version

1.45.20

### Browser

Firefox

### Console Errors

```javascript

```

### Logs

```shell

```

### Additional Context

_No response_

Start by reproducing the issue in Firefox for Android with the URL bar at the bottom, using a multiline text input until its contents scroll. Trace the frontend canvas and viewport layout behavior during editing and verify that the top controls remain reachable, the bottom area does not grow unexpectedly, and switching workflows is no longer needed to restore the layout.

Written by the indexing model from the issue text.