server fix

client/src/main.rs

@@ -37,7 +37,8 @@ async fn main() -> Result<()> {
         // file → non‑blocking writer (+ guard)
         let file = OpenOptions::new()
             .create(true)
-            .append(true)
+            .write(true)
+            .truncate(true)
             .open(&log_path)?;
         let (file_writer, guard) = non_blocking(file);
         _guard = Some(guard);