fix(deploy): split ingress to oolon, expose api on nikola interface

The per-site nginx ingress for rob.tn lives on oolon (the host the
external router forwards 443 traffic to), not on nikola. Adjust the
topology so:

- web (static ui + nginx) → oolon.hanzalova.internal
- api binds 0.0.0.0:42424 on nikola.kosherinata.internal so oolon
  can reverse-proxy across the WG mesh
- new firewalld service moments-api opens 42424 in the default zone
  on nikola
- oolon labels port 42424 http_port_t so httpd_t may name_connect
  outbound to it (httpd_can_network_connect was already set)
- nginx ssl_certificate switched to oolon's host cert; upstream
  rewritten to nikola.kosherinata.internal:42424

Plaintext between oolon and nikola for now — the WG mesh provides
the encryption layer and the data is already public. Documented
the deferral so a future move to per-hop mTLS is obvious.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

asset/config/api.env.tmpl

@@ -4,6 +4,6 @@
 JOURNAL_STREAM=1
 RUST_LOG=info,sqlx=warn,tower_http=info
 
-BIND_ADDR=127.0.0.1:42424
+BIND_ADDR=0.0.0.0:42424
 
 DATABASE_URL=postgres://moments_ro@magrathea.kosherinata.internal:5432/moments?sslmode=verify-full&sslrootcert=/etc/pki/ca-trust/source/anchors/root-internal.pem&sslcert=/etc/pki/tls/misc/{{HOSTNAME}}.pem&sslkey=/etc/pki/tls/private/{{HOSTNAME}}.pem