Voila prerender doesn't support markdown JupyterLab commands

[davidkan6666]

When using markdown cells containing JupyterLab commands, after being rendered by Voila, the required JavaScript libraries appear no longer available and result in errors like:

Command 'notebook:clear-all-cell-outputs' not registered Command 'help:about' not registered

How to reproduce it?

1. create a test notebook
2. add the following code in Markdown cell: `START STOP CLEAR About`
3. run the cell in the notebook
4. buttons work
5. now open notebook with Voila Prerender
6. click on any button will result in something like "Uncaught (in promise) Error: Command 'help:about' not registered" from developer tool (F12) Console.

• voila version 0.5.7
• Operating System and version: Microsoft Windows 10
• Browser and version: Chrome Version 128.0.6613.139 (Official Build) (64-bit) and FireFox 130.0.1 (64-bit)

Browser Output

2168.voila.js:1 Uncaught (in promise) Error: Command 'help:about' not registered.
    at d.execute (2168.voila.js:1:2959)
    at L._evtClick (1024.voila.js:1:35883)
    at L.handleEvent (1024.voila.js:1:35512)
2168.voila.js:1 Uncaught (in promise) Error: Command 'notebook:run-all-below' not registered.
    at d.execute (2168.voila.js:1:2959)
    at L._evtClick (1024.voila.js:1:35883)
    at L.handleEvent (1024.voila.js:1:35512)
2168.voila.js:1 Uncaught (in promise) Error: Command 'kernelmenu:interrupt' not registered.
    at d.execute (2168.voila.js:1:2959)
    at L._evtClick (1024.voila.js:1:35883)
    at L.handleEvent (1024.voila.js:1:35512)
2168.voila.js:1 Uncaught (in promise) Error: Command 'notebook:clear-all-cell-outputs' not registered.
    at d.execute (2168.voila.js:1:2959)
    at L._evtClick (1024.voila.js:1:35883)
    at L.handleEvent (1024.voila.js:1:35512)

• JupyterLab version: 4.2.5

Installed Labextensions

        jupyterlab_pygments v0.3.0 enabled OK (python, jupyterlab_pygments)
        @jupyter-widgets/jupyterlab-manager v5.0.13 enabled OK (python, jupyterlab_widgets)
        @voila-dashboards/jupyterlab-preview v2.3.7 enabled OK (python, voila)
        @jupyter-notebook/lab-extension v7.1.3 enabled OK

[fomightez]

Discussion thread related to this issue is here on the Jupyter Discourse Forum.