OpenUI MC 0.0.16

• Restore virtual dispatch of the public UIComponent.preRender(mouseX, mouseY) callback while traversing clipped child trees. This fixes consumer-owned pre-render updates, including dynamic tooltips, that were accidentally skipped by the private dispatcher.
• Preserve ancestor clip eligibility for hover transitions through nested containers, suppress invisible descendant hover, and restore transient eligibility after each child dispatch (including on exceptions).
• Add subclass callback, nested clipping, and pointer re-entry regressions for 1.20.1, 1.21.1 and the shared 26.x modern implementation.
• Clarify that custom preRender overrides must call super.preRender(mouseX, mouseY) to retain default hover updates and child traversal.

This is a new release version. Do not overwrite the previously published 0.0.15 artifacts.