The svg icon is only a wrapper around app-icon.png, and the nested
reference is invisible to the static copy step, so the image stayed
invisible on production even after the svg itself deployed.
The docs header logo and favicon 404 on production because the
static copy step only scanned markdown for image references. Scan
site sources as well and fail the build when one goes missing.
- rebuild home and docs UI around serif display type, warm paper,
and a single vermilion accent
- rewrite zh/en landing copy around user value
- fix white screen on the last docs page (adjacent-doc out of bounds)
- curate sidebar labels and add TOC scroll-spy
