fix(jb): prevent white flash on GUI load

[Patrick-Erichsen]

Description

One line fix was setting this: setOffScreenRendering(true)

this.browser = JBCefBrowser.createBuilder().setOffScreenRendering(true).build()

Checklist

• [ ] The base branch of this PR is dev, rather than main
• [ ] The relevant docs, if any, have been updated or created

Screenshots

[ For visual changes, include screenshots. ]

Testing

[ For new or modified features, provide step-by-step testing instructions to validate the intended behavior of the change. ]