7ca6ee0's favicon.svg had a comment naming the `--fc-chrome-rgb` custom property. `--` is illegal inside an XML comment, so the file is not well-formed XML, and a browser renders an SVG-as-image only if it parses. It fails without any error, just a blank image. Because TopNav's brand glyph is the same file, the tab icon and the nav mark both went missing on the #251 deploy. logo.svg parses and was unaffected.
The comment now names the property without the hyphens, and says why it has to.
tests/test_public_svgs.py parses every SVG under frontend/public. It includes a vacuity guard (the directory really contains the two known files) and a positive control (the exact defect raises ParseError), so the check can actually fail.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SHQB1YukL3VyvMK8rcbmV9
