fix(rustproxy-http,rustproxy-metrics): fix domain-scoped request host detection and harden connection metrics cleanup

rust/crates/rustproxy-http/src/counting_body.rs

@@ -1,8 +1,8 @@
 //! A body wrapper that counts bytes flowing through and reports them to MetricsCollector.
 
 use std::pin::Pin;
-use std::sync::Arc;
 use std::sync::atomic::{AtomicU64, Ordering};
+use std::sync::Arc;
 use std::task::{Context, Poll};
 
 use bytes::Bytes;
@@ -76,7 +76,11 @@ impl<B> CountingBody<B> {
     /// Set the connection-level activity tracker. When set, each data frame
     /// updates this timestamp to prevent the idle watchdog from killing the
     /// connection during active body streaming.
-    pub fn with_connection_activity(mut self, activity: Arc<AtomicU64>, start: std::time::Instant) -> Self {
+    pub fn with_connection_activity(
+        mut self,
+        activity: Arc<AtomicU64>,
+        start: std::time::Instant,
+    ) -> Self {
         self.connection_activity = Some(activity);
         self.activity_start = Some(start);
         self
@@ -134,7 +138,9 @@ where
                     }
                     // Keep the connection-level idle watchdog alive on every frame
                     // (this is just one atomic store — cheap enough per-frame)
-                    if let (Some(activity), Some(start)) = (&this.connection_activity, &this.activity_start) {
+                    if let (Some(activity), Some(start)) =
+                        (&this.connection_activity, &this.activity_start)
+                    {
                         activity.store(start.elapsed().as_millis() as u64, Ordering::Relaxed);
                     }
                 }