feat: Live preview editing mode for PreviewView

[distantnative]

Description

Merge first

• feat: Follow navigation in preview view #7550
• refact!: Change versionId → mode preview view #7795
• fix: Writer toolbar position without Panel menu #7799
• refact: k-panel-notifications #7797
• refact: Model tabs reload view instead link #7798
• feat: $panel.urls.panel state #7800
• refact: k-button apply all aria- attributes #7801

Changelog

🎉 Features

• Preview view: new mode that let's you edit your pages right next to its live preview
  • Preview mode syncs navigation in the browser(s)
  • Open preview in the browser window, still live previews changes
  • Preview your site in different viewport widths in the preview view
  • New panel.preview.sizes option to define custom viewport sizes

Screen.Recording.2025-12-20.at.14.04.07.mp4

🚨 Breaking changes

For review team

• Add changes & docs to release notes draft in Notion

[distantnative]

@bastianallgeier Would be great to have a first review round with this.

[bastianallgeier]

First impressions:

• It's AWESOME!!
• We might need a new tablet icon. It looks very close to the phone icon.
  
• I'm a bit astonished by some of our breakpoint choices for the columns grid.
  
• I wonder if we could use something more fancy for the dropdown label instead of "Edit content". Maybe something like "Live Editor"
  
• I'm still a bit hesitant about the model tab change, but the rest looks very clean to me.