The anchor pass added in f911b5f runs on every element's children — including
UiRoot's children, which are the top-level WINDOWS. With the default Left|Top
anchor, ApplyAnchor reset each window's Left/Top/Width/Height back to its
captured design rect EVERY frame, so user move/resize was undone instantly ("I
can't resize or move it"). A window is user-positioned, so it must not be
anchor-managed by its parent: set UiNineSlicePanel.Anchors = None. Children
INSIDE the window still anchor to it (the bars keep stretching with width).
Regression tests: UiNineSlicePanel.Anchors == None; ApplyAnchor(None) is a no-op.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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