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

crates/newsfeed-api/src/config.rs

@@ -30,7 +30,7 @@ pub struct Config {
 impl Default for Config {
     fn default() -> Self {
         Self {
-            bind: "127.0.0.1:8081".parse().expect("valid default bind addr"),
+            bind: "127.0.0.1:22672".parse().expect("valid default bind addr"),
             database_path: PathBuf::from("/var/lib/newsfeed/newsfeed.db"),
             session_ttl_days: 30,
             max_db_connections: 5,
@@ -42,7 +42,7 @@ impl Default for Config {
 
 impl Config {
     /// Load configuration, layering an optional TOML file and the environment over the
-    /// defaults. Env vars are `NEWSFEED_` prefixed (e.g. `NEWSFEED_BIND=0.0.0.0:8081`).
+    /// defaults. Env vars are `NEWSFEED_` prefixed (e.g. `NEWSFEED_BIND=0.0.0.0:22672`).
     pub fn load(file: Option<&Path>) -> anyhow::Result<Self> {
         let mut fig = Figment::from(Serialized::defaults(Config::default()));
         if let Some(path) = file {