The Caddyfile created a server with an auto-generated name, not 'hiy',
so build.sh's PUT to /config/apps/http/servers/hiy/routes was creating
a parallel server that never received traffic.
- Replace Caddyfile with caddy.json that names the server 'hiy' with
the dashboard as a catch-all fallback route
- Insert app routes at index 0 so host-matched routes are evaluated
before the catch-all dashboard fallback
- Update docker-compose to mount caddy.json and pass --config flag
