FR: eAmbrosia register as a second cahier source + keyed CARTO basemap - #24

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, actions/setup-node@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

'frMarker' is defined but never used

'grapeSynonymsHtml' is defined but never used

'SLUG_TO_CANONICAL' is assigned a value but never used

'FACET_GRAPES_ALL' is assigned a value but never used

'FACET_ACCESSORY' is assigned a value but never used