strip_svg_hyperlinks() removed every href, including on <image>
elements that reference device-type photos, leaving devices with
images blank in the exported file. Non-anchor hrefs (currently only
<image>) are now resolved through an optional image_loader callback
and embedded as base64 data URIs instead of being stripped; anchor
unwrapping is unchanged. RackElevationOfflineSVGView wires this up to
NetBox's MEDIA storage.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>