TEST-ONLY: parse rawSvgText once (same prep __renderActiveLayers does —
strip display:none to data-active, seed missing data-active defaults) and
return the live parsed element. Pair with __renderActiveLayersOnNode to
render multiple states onto the SAME node, reproducing how the live app
reuses one persistent SVG DOM node per tooth across renders (unlike
__renderActiveLayers, which re-parses a fresh node every call and so
cannot catch a render that fails to reset state a prior render left
behind). Not part of the public API.
TEST-ONLY: parse
rawSvgTextonce (same prep__renderActiveLayersdoes — strip display:none to data-active, seed missing data-active defaults) and return the live parsed element. Pair with__renderActiveLayersOnNodeto render multiple states onto the SAME node, reproducing how the live app reuses one persistent SVG DOM node per tooth across renders (unlike__renderActiveLayers, which re-parses a fresh node every call and so cannot catch a render that fails to reset state a prior render left behind). Not part of the public API.