loadGroup
Loads the SVG document at path as a scene sub-tree.
The document parses in the /v1 SVG format via parseSvg. External <use href="doc.svg"> templates resolve transparently: the document is scanned for references, each referenced document is fetched relative to this document's directory — hrefs are plain sibling file names, so a document at files/scene.svg referencing tile.svg reads files/tile.svg — fetched templates are re-scanned for transitive references, and the document parses once with the full template map. A reference cycle fails the parse with SvgTemplateCycleException; text that is not well-formed XML fails below the format layer with the underlying reader's XmlException.
Return
The document as a GroupNode: children in source order, bounds carrying the viewBox.
Parameters
The document's resource path.
Throws
when a document violates the /v1 format — every failure is a subtype naming its condition.