Replace prints with logs and fix grammar (#437)

* refactor: replace print statements with proper logging and fix grammar

- Fix English grammar errors in existing log messages
- Add tracing imports where needed
- Improve log message clarity and consistency
- Follow project logging best practices using tracing crate

* fix: resolve clippy warnings and format code

- Fix unused import warnings by making test imports conditional with #[cfg(test)]
- Fix unused variable warning by prefixing with underscore
- Run cargo fmt to fix formatting issues
- Ensure all code passes clippy checks with -D warnings flag

* refactor: move tracing::debug import into test module

Move the tracing::debug import from file-level #[cfg(test)] into the test module itself for better code organization and consistency with other test modules

* Checkpoint before follow-up message

Co-authored-by: anzhengchao <anzhengchao@gmail.com>

* refactor: move tracing::debug import into test module in user_agent.rs

Complete the refactoring by moving the tracing::debug import from file-level #[cfg(test)] into the test module for consistency across all test files

---------

Co-authored-by: Cursor Agent <cursoragent@cursor.com>

crates/utils/src/io.rs

@@ -110,6 +110,7 @@ pub fn uvarint(buf: &[u8]) -> (u64, isize) {
 mod tests {
     use super::*;
     use tokio::io::BufReader;
+    use tracing::debug;
 
     #[tokio::test]
     async fn test_read_full_exact() {
@@ -130,7 +131,7 @@ mod tests {
             rev[total - n..total].copy_from_slice(&buf[..n]);
 
             count += 1;
-            println!("count: {count}, total: {total}, n: {n}");
+            debug!("Read progress - count: {}, total: {}, bytes read: {}", count, total, n);
         }
         assert_eq!(total, size);