Replace project sections with live Services list

- Add services.json: hand-maintained source of truth with 20 public
  homelab services across 7 categories (edge, observability, media,
  downloads, ethereum, ai, dev), each with name/url/desc/icon.
- Rewrite index.html: Services section rendered client-side from
  services.json with a tiny up/down status probe (green dot = up,
  grey = down/unreachable; graceful fallback on CORS/offline).
  Keep a small Projects section linking the GitHub orgs so the old
  content is not lost.
- Add services grid + status dot styles to styles.css.
- Dockerfile: COPY services.json into the nginx html root.

Dockerfile

@@ -3,7 +3,7 @@ FROM nginx:1.27-alpine
 LABEL org.opencontainers.image.title="ffaerber/homepage" \
       org.opencontainers.image.source="https://git.ffaerber.duckdns.org/ffaerber/homepage"
 
-COPY index.html styles.css /usr/share/nginx/html/
+COPY index.html styles.css services.json /usr/share/nginx/html/
 
 EXPOSE 80