KML icons use relative paths and load as broken images

• The network panel shows GET /cookbook/images/pin.png 404 and every point renders the browser's broken-image glyph.
• The same KML opens correctly in Google Earth, which resolves against the file location.
• The icon should have been requested from /data/images/pin.png.

1. Filter the network panel by png and note the full path of the 404.
2. Compare that path with the KML's own URL to see which base directory was used.
3. Search the KML for <href> to see whether it is absolute, relative or a file:// URL.
4. Confirm that <IconStyle> exists at all, since some exporters write no icon.
5. Re-resolve the href against the KML URL and request the resulting path directly.

Make href absolute such as /data/images/pin.png, or inline the image as a data URI. When parsing, rewrite with new URL(href, kmlUrl).href inside pointToLayer before building L.icon with iconUrl and iconSize [24, 24].

<Style id="s1">
  <IconStyle>
    <scale>1.0</scale>
    <Icon><href>images/pin.png</href></Icon>
  </IconStyle>
</Style>

<!-- 改成绝对路径（同源） -->
<Icon><href>/data/images/pin.png</href></Icon>

<!-- 或者内联成 data URI，彻底摆脱路径问题 -->
<Icon><href>data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQ...</href></Icon>

• Fixing only the local path: the same relative href breaks as soon as the KML moves to another directory or domain.
• Blindly replacing the icon path while other <href> entries point at legitimate network links.