ipx-play's metrics on 9191: 9189 is hnopml's (#458)

5d0ff1a put ipx-play's /metrics on 9189, but hnopml, in the same
compose project, has published 192.168.1.130:9189 since 2026-11-12 and
Prometheus scrapes it there as job="hnopml". Deployed as written,
ipx-play's port would have clashed with it. 9187 to 9190 are ipx, the
directory, hnopml and ipx-web; 9191 is free.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/play/src/config.rs

@@ -16,7 +16,7 @@ pub struct Config {
     #[serde(default = "default_database_url_env")]
     pub database_url_env: String,
     /// Where to serve /metrics for Prometheus (#458), apart from `bind`, which the tunnel
-    /// publishes: `0.0.0.0:9189`. Empty serves none.
+    /// publishes: `0.0.0.0:9191`. Empty serves none.
     #[serde(default)]
     pub metrics_bind: String,
     /// The address people open, which the links ipx is handed begin with.