This *should be* obvious, but sometimes the obvious isn't always to this
observer.  :)

    <xsl:template name="detail">
      <xsl:param name="category" />
        <xsl:for-each select='/config/option[@class="$category"]'>

                                               ^^^^^^^^^^^^^^^^^^
This matches options whose class attribute is the string $category,
rather than the value of the parameter named category.
Use
         <xsl:for-each select='/config/option[@class=$category]'>
instead.