[qt/qt/qtquick3d]: Summary of bulk changes made

Git repository change summary for qt/qt/qtquick3d
Pushed by mirror-service into branch '6.11'.
Changed from 8dce74d3685a9ec9a9e2d5b4d86bd8d57d72b331 to aeb48cb4760f1a37ef03a2ac3011116e4c2e7daf
Acknowledgement was received that this change introduces only existing code that has been pushed to another public open source repository.

This change contains the following new commits:

Git commit 8f3e00ecbbc4e56debdf6a8c220d5bc207393258 by Qt Cherry-pick Bot (on behalf of Christian Strømme) on 24/07/2026 at 19:31..
Make sure we mark the tree dirty when adding/removing an import-scene

The import scene injects itself into the layer's child list by setting
the dummy import-scene node's head and tail directly, deliberately
avoiding the normal add/remove path so the imported root's sibling
links and rootNodeRef aren't modified.

Mark the tree dirty explicitly in both setImportScene() and
removeImportScene() so the change triggers the needed reindex. On
removal we also reset the imported node's handle; we must not clear the
node's Imported state or rootNodeRef, as the node may be imported by
more than one view and neither is restored by the per-frame update.

The dummy import-scene node itself is added through addChild(), which
now front-inserts ImportScene nodes so the imported scene always gets
the lowest indices. That keeps a shared imported scene at the start
of a shared data store regardless of how many nodes a given view holds.
While here, simplify addChild()'s reparenting guard to only special-
case layer nodes.

Add tests covering the add/remove state transitions and the multi-view
sharing case.

Change-Id: Ie1e5b063f7b64df06a26a57b074ba7b83d137dcf
Reviewed-by: Andy Nichols <[email protected]>
(cherry picked from commit 53c4de134c67fb3e468869acb325105ec0817b65)
Reviewed-by: Qt Cherry-pick Bot <[email protected]>
(cherry picked from commit 9abfb594260023d9f5e56859dd910415117be2b2)
https://invent.kde.org/qt/qt/qtquick3d/-/commit/8f3e00ecbbc4e56debdf6a8c220d5bc207393258

Git commit aeb48cb4760f1a37ef03a2ac3011116e4c2e7daf by Qt Cherry-pick Bot (on behalf of Christian Strømme) on 24/07/2026 at 19:31..
Remove uncommented code in refSceneManager

This code haven't been used since the initial commit, so just get rid of
it.

Change-Id: Id1d07380d7b3127716f60189a0d19dadf03c9ae4
Reviewed-by: Andy Nichols <[email protected]>
(cherry picked from commit 7c2fcd2574ac33060bf3ace55ee2aa9a2733856e)
Reviewed-by: Qt Cherry-pick Bot <[email protected]>
(cherry picked from commit 0dfa4e269cfa0be87fc823e74e6af4b62cb7c973)
https://invent.kde.org/qt/qt/qtquick3d/-/commit/aeb48cb4760f1a37ef03a2ac3011116e4c2e7daf