наблюдаемость: ввести безопасный контракт метрик

apps/mcp-server/src/lib.rs

@@ -0,0 +1 @@
+pub mod pool_metrics;

apps/mcp-server/src/main.rs

@@ -13,7 +13,8 @@ use crank_runtime::{
     RequestRateLimitConfig, RequestRateLimiter, RuntimeCacheConfig, RuntimeCacheStores,
     RuntimeLimits, SecretCrypto,
 };
-use sqlx::{PgPool, postgres::PgConnectOptions};
+use mcp_server::pool_metrics::spawn_postgres_pool_metrics;
+use sqlx::postgres::PgConnectOptions;
 use tokio::net::TcpListener;
 use tracing::info;
 
@@ -162,13 +163,3 @@ fn mcp_api_rate_limit_config_from_env() -> Result<RequestRateLimitConfig, Box<dy
 
     Ok(RequestRateLimitConfig::new(requests_per_second, burst)?)
 }
-
-fn spawn_postgres_pool_metrics(pool: PgPool) {
-    tokio::spawn(async move {
-        let mut interval = tokio::time::interval(Duration::from_secs(5));
-        loop {
-            interval.tick().await;
-            crank_observability::record_db_pool_connections(pool.size(), pool.num_idle());
-        }
-    });
-}

apps/mcp-server/src/pool_metrics.rs

@@ -0,0 +1,13 @@
+use std::time::Duration;
+
+use sqlx::PgPool;
+
+pub fn spawn_postgres_pool_metrics(pool: PgPool) -> tokio::task::JoinHandle<()> {
+    tokio::spawn(async move {
+        let mut interval = tokio::time::interval(Duration::from_secs(5));
+        loop {
+            interval.tick().await;
+            crank_observability::record_db_pool_connections(pool.size(), pool.num_idle());
+        }
+    })
+}