This is a common problem in the front-end: any "DOM control node" that carries an expired .width attribute will result in blank space on the right side.

### Prerequisites

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

### What happened?

This is a common problem in the front-end: any "DOM control node" that carries an expired .width attribute will result in blank space on the right side. I confirmed the common mechanism in the ComfyUI frontend (GraphView-Cc2GkGnZ.js): When the 'updateWidgets' function calculates the element width for each DOM control, it uses:

js
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( widget.width ?? node.width ) - 2*margin
That is to say, as long as this DOM control carries its own expired .width, the element will not expand to fill the entire node border - the panel will only occupy a part on the left and leave a blank space on the right. This is the common root cause of both Media Loader and KJ's "Model Preview Override".
The solution is the same for both: Make the .width of the control follow the node width frame by frame, so that ${widget.width} ?? node.width is equal to the node width, and the control element fills the entire border.
Modified:

Media Loader: ComfyUI-MiniMax-ContextIR\web\fant_medialoader.js (v6: this._mmlWidget.width = this.size[0])
KJ Model Preview Override: ComfyUI-KJNodes\web\js\preview_override\preview_override.js (New: povWidget.width = node.size[0] is synchronized frame by frame, and is cancelled when onRemoved is triggered)
Please test

### Steps to Reproduce

1.The width of the DOM control element = widget.width ?? node.width. That is: if the control has its own .width, use the control's width instead of the node's width.

Our Media Loader panel control has an outdated/small .width, so its element (as well as the .mml-panel with width:100%!important) is only filled to that width, while the node border is wider → there is a 1/3 blank space on the right.

The onResize/each-frame pin (v4/v5) that I previously modified was changing node.size, but the direction was wrong - because the actual width that determines the panel is widget.width, not node.size.
2.
3.

### Workflow

N/A

### How is this affecting you?

Crashes ComfyUI completely

### ComfyUI Frontend Version

1.51.9

### Browser

Edge

### Console Errors

```javascript

```

### Logs

```shell

```

### Additional Context

_No response_

Start by inspecting updateWidgets in GraphView-Cc2GkGnZ.js to confirm how widget.width and node.width determine DOM control sizing. Then review fant_medialoader.js and preview_override.js, verify that each control width tracks the node width throughout resizing, and test that the right-side blank space no longer appears.

Written by the indexing model from the issue text.