Server-side Supabase calls (middleware getUser/refresh, server components,
admin client) all egress through the Docker gateway as a single NATed IP and
traverse Caddy's per-IP /auth/* rate limiter (8 events/s). A handful of active
users saturate that shared bucket, 429ing getUser()/token refresh; the
middleware then treats the session as invalid and bounces to /login, while a
manual refresh lands under budget and works again.
Add SUPABASE_INTERNAL_URL (e.g. http://kong-prod:8000) used only by the
server-side clients (middleware, lib/supabase/server.ts, admin getSupabaseAdmin
/getSupabaseAnon), falling back to the public URL when unset. Browser clients
keep the public URL so real per-user-IP edge rate limiting still applies.
Also bake the arg in the Dockerfile/build and make the web-prod network alias
durable via WEB_ALIAS (dev sets web-dev) so the dev container can't reclaim the
web-prod alias on redeploy.