PPTX: connector shapes (cxnSp) and DOCX: VML horizontal rules (v:rect) not rendered

[developer0hye]

Description

Two related issues where line/separator elements are completely missing from conversion output:

PPTX: <p:cxnSp> connector shapes

Connector shapes (horizontal/vertical lines, arrows between shapes) are not parsed. Searching for cxnSp in pptx.rs yields zero matches.

PPTX XML structure:

<p:cxnSp>
  <p:nvCxnSpPr>
    <p:cNvPr id="9" name="Connector"/>
    <p:cNvCxnSpPr><a:cxnSpLocks/></p:cNvCxnSpPr>
    <p:nvPr/>
  </p:nvCxnSpPr>
  <p:spPr>
    <a:xfrm>
      <a:off x="2438400" y="2670618"/>
      <a:ext cx="9753600" cy="0"/>
    </a:xfrm>
    <a:prstGeom prst="line"><a:avLst/></a:prstGeom>
    <a:ln w="38100">
      <a:solidFill><a:srgbClr val="0D0D0D"/></a:solidFill>
    </a:ln>
  </p:spPr>
</p:cxnSp>

Expected: A thick dark horizontal line across the slide.
Actual: Nothing rendered — the line is completely missing.

This also affects <p:cxnSp> elements inside group shapes (<p:grpSp>).

DOCX: <w:pict>/<v:rect> VML horizontal rules

DOCX documents using VML-based horizontal rules are not rendered. Searching for w:pict and v:rect in docx.rs yields zero matches.

DOCX XML structure:

<w:r>
  <w:pict>
    <v:rect style="width:0.0pt;height:1.5pt"
            o:hr="t" o:hrstd="t" o:hralign="center"
            fillcolor="#A0A0A0" stroked="f"/>
  </w:pict>
</w:r>

Expected: A thin gray horizontal separator line.
Actual: Nothing rendered.

Impact

Horizontal separators are very common in both PPTX slides (section dividers, decorative lines) and DOCX documents (section breaks, title separators). Missing them significantly degrades visual fidelity.