Lock editor group when opening integrated browser side-by-side

[Copilot]

When opening Integrated Browser with openToSide: true, the editor group was not locked, causing newly opened editors to replace the browser if it was focused. This breaks parity with the previous Live Preview extension behavior.

Changes

Modified OpenIntegratedBrowserAction in browserViewActions.ts:

const editorPane = await editorService.openEditor({ resource }, group);

// Lock the group when opening to the side
if (options.openToSide && editorPane?.group) {
    editorPane.group.lock(true);
}

The group is now automatically locked when openToSide: true, preventing editors from opening in the browser's group when the browser is focused. Users can manually unlock via the UI if desired.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Integrated Browser + Live Preview: opened side-by-side window should have "Lock group"</issue_title>
<issue_description>In the old experience, the browser is opened on the side with a Locked group. In the new experience with Integrated Browser, it's not opened with a locked group.

The reason why a locked group is useful is so that newly opened editors don't open on the same group as the browser, even if the browser is focused.

---

Old experience -- note the Locked Group icon:

New experience -- note no Locked Group icon:

</issue_description>

<agent_instructions>When someone calls command INTEGRATED_BROWSER_COMMAND with openToSide: true, the browser editor group that's opened to the side should have a locked group (similar to what's accomplished by 'workbench.action.lockGroup' command, but if there's a cleaner way to do it that would be best)</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Integrated Browser + Live Preview: opened side-by-side window should have "Lock group" #295837

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[Copilot]

Pull request overview

This PR restores parity with the Live Preview extension by automatically locking the editor group when the Integrated Browser is opened side-by-side. This prevents newly opened editors from replacing the browser when it has focus.

Changes:

• Modified OpenIntegratedBrowserAction to lock the editor group automatically when openToSide: true is specified