fix: move newsfeed-api off 8081 to 22672 (conflict-unlikely port)

8081 is the alt-HTTP port — one of the crowded defaults every proxy/dev server
grabs — so it's collision-prone on a shared host. Move to 22672, a registered-
range port in the sparse 20000s band, derived deterministically from the
service name and recorded in architecture port-allocations.md.

Updated everywhere the number appears: api bind config + default, firewalld
service XML, nginx upstream, vite dev proxy, deploy workflow API_PORT,
infra-setup (SELinux semanage label), and docs.

Operator note: re-run script/infra-setup.sh on slartibartfast to relabel the
SELinux port (22672) and ship the updated firewalld XML before the next deploy
restarts the api on the new port.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016fKZzDpvjiJ9eYbPGgJvUP

CLAUDE.md

@@ -57,7 +57,8 @@ Crypto/token logic lives in `core::auth`; the flow orchestration in `core::servi
 
 api + worker → `slartibartfast.kosherinata.internal`; SPA → `oolon.kosherinata.internal`
 (nginx serves + proxies `/v1` to the API over the mesh; TLS terminates at oolon). API
-port 8081, plain HTTP behind firewalld. See `.gitea/workflows/deploy.yml` (infra truth)
+port 22672 (registered in architecture `port-allocations.md`; deliberately not the crowded
+`8081`), plain HTTP behind firewalld. See `.gitea/workflows/deploy.yml` (infra truth)
 and `script/infra-setup.sh` (one-time host prep). `Type=exec`, not `notify`, because axum
 doesn't `sd_notify`.