perf: simplify method signatures and reduce clone across multiple files (#1663)

easytier/src/common/stats_manager.rs

@@ -509,7 +509,7 @@ impl StatsManager {
         let counters = Arc::new(DashMap::new());
 
         // Start cleanup task only if we're in a tokio runtime
-        let counters_clone = Arc::downgrade(&counters.clone());
+        let counters_clone = Arc::downgrade(&counters);
         let cleanup_task = tokio::spawn(async move {
             let mut interval = interval(Duration::from_secs(60)); // Check every minute
             loop {

easytier/src/common/tracing_rolling_appender/mod.rs

@@ -90,7 +90,7 @@ where
 
     /// Rotates old files to make room for a new one.
     /// This may result in the deletion of the oldest file
-    fn rotate_files(&mut self) -> io::Result<()> {
+    fn rotate_files(&self) -> io::Result<()> {
         // ignore any failure removing the oldest file (may not exist)
         let _ = fs::remove_file(self.filename_for(self.max_filecount.max(1)));
         let mut r = Ok(());