Unused named template

A named template that is never invoked via xsl:call-template is dead code and should be removed.

This is a cross-file check: it looks at every stylesheet linted together, so a template invoked from another file (via xsl:import or xsl:include) is not reported. The template is flagged only when no file calls it. Lint the whole project at once so the check can see every caller.

Incorrect:

<xsl:template name="footer">
  <footer>Copyright 2026</footer>
</xsl:template>
<!-- xsl:call-template name="footer" never appears in this stylesheet -->

Correct:

<xsl:template name="footer">
  <footer>Copyright 2026</footer>
</xsl:template>

<xsl:template match="/">
  <xsl:call-template name="footer"/>
</xsl:template>