Node selection with Alt + ArrowLeft, Alt + ArrowRight can't be used for keybinding

### Prerequisites

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

### What happened?

System : Windows ComfyUI Desktop

I have done an extension that use shortcuts for aligning nodes, and it works.
However during my test, it seems I can't assign `Alt + ArrowLeft ` and `Alt + ArrowRight ` as shortcuts, other key bindings work.
Even with the keybindings manager in settings, `Alt + ArrowLeft ` and `Alt + ArrowRight ` show no errors and I can assign them to other keybindings to make it work.
But it works with `Alt + ArrowDown` and `Alt + ArrowUp`

**A hint, it works on native key bindings like "Save Workflow", but NOT when there is selected nodes** .

And it don't seem the documentation have this combo. I search in :

- https://github.com/Comfy-Org/ComfyUI_frontend/blob/e76e9ec61a068fd2d89797762f08ee551e6d84a0/src/constants/coreKeybindings.ts

- https://github.com/Comfy-Org/ComfyUI_frontend/blob/e76e9ec61a068fd2d89797762f08ee551e6d84a0/src/constants/coreMenuCommands.ts

- https://github.com/Comfy-Org/ComfyUI_frontend/blob/e76e9ec61a068fd2d89797762f08ee551e6d84a0/src/composables/useCoreCommands.ts

- https://github.com/Comfy-Org/ComfyUI_frontend/blob/e76e9ec61a068fd2d89797762f08ee551e6d84a0/src/constants/reservedKeyCombos.ts

Also, there is any errors when using reserved keybindings, could be great an error in the console or somewhere for extensions (documentation a bit vague that say undefined beetween extensions, but not about with the native keybindings).

### Steps to Reproduce

1. Go on Settings > keybinding
2. Assign a binding as Alt + ArrowLeft/ArrowRight
3. Select nodes
4. Use keybinding

### How is this affecting you?

Crashes ComfyUI completely

### ComfyUI Frontend Version

1.42.15

### Browser

Other

### Console Errors

```javascript
None
```

### Logs

```shell
None
```

### Additional Context

[ComfyUI v0.20.1](https://github.com/comfyanonymous/ComfyUI)
[ComfyUI_frontend v1.42.15](https://github.com/Comfy-Org/ComfyUI_frontend)
[Templates v0.9.63](https://pypi.org/project/comfyui-workflow-templates/)
[ComfyUI_desktop v0.8.36](https://github.com/Comfy-Org/electron)
[LoRA Manager v1.0.6-stable](https://github.com/willmiao/ComfyUI-Lora-Manager)
[EasyUse v1.3.6](https://github.com/yolain/ComfyUI-Easy-Use)
[rgthree-comfy v1.0.2605082257](https://github.com/rgthree/rgthree-comfy)

## System Info
OS: win32
Python Version: 3.12.11 (main, Aug 18 2025, 19:17:54) [MSC v.1944 64 bit (AMD64)]
Embedded Python: false
Pytorch Version: 2.8.0+cu129
Arguments: C:\Users\marc2\AppData\Local\Programs\ComfyUI\resources\ComfyUI\main.py --user-directory C:\ComfyUI\user --input-directory C:\ComfyUI\input --output-directory C:\ComfyUI\output --front-end-root C:\Users\marc2\AppData\Local\Programs\ComfyUI\resources\ComfyUI\web_custom_versions\desktop_app --base-directory C:\ComfyUI --database-url sqlite:///C:/ComfyUI/user/comfyui.db --extra-model-paths-config C:\Users\marc2\AppData\Roaming\ComfyUI\extra_models_config.yaml --log-stdout --listen 127.0.0.1 --port 8008 --enable-manager
RAM Total: 31.84 GB
RAM Free: 2.89 GB
Templates Version: 0.9.63

## Devices
- cuda:0 NVIDIA GeForce RTX 3060 Ti : cudaMallocAsync (cuda)
VRAM Total: 8 GB
VRAM Free: 6.97 GB
Torch VRAM Total: 0 B
Torch VRAM Free: 0 B

┆Issue is synchronized with this [Notion page](https://www.notion.so/Issue-12112-Node-selection-with-Alt-ArrowLeft-Alt-ArrowRight-can-t-be-used-for-keybinding-35b6d73d36508173b1ffea78912dc87d) by [Unito](https://www.unito.io)