homepage: live model info on the fleet cards, user docs page at /docs

- services.json: frank-large/medium/small move from admin-only to the user
  page with current descriptions (halogen w4b iGPU; 35:30 layer-split MTP
  27B on the R9700s; Gemma4-12B QAT vision path on the 3090) and docs
  links to /docs#models
- docs.html: static user documentation (access chain, model guide, media
  how-tos, troubleshooting); served at /docs via the post-auth homepage
  listener; shipped by deploy_homepage; footer + index link to it
- tests: pages seam asserts the docs contract (page, link, Caddy route,
  deployer copy)
- vault: Homepage.md synced (docs landing shipped, cards reclassified)

scripts/deploy-remote.sh

@@ -302,7 +302,7 @@ deploy_homepage() {
     fi
     run_privileged mkdir -p /srv/homepage
     run_privileged cp shared/homepage/index.html shared/homepage/admin.html shared/homepage/app.js \
-        shared/homepage/style.css shared/homepage/services.json /srv/homepage/
+        shared/homepage/style.css shared/homepage/services.json shared/homepage/docs.html /srv/homepage/
     if [[ -d shared/homepage/fonts ]]; then
         run_privileged cp -r shared/homepage/fonts /srv/homepage/
     fi