Fix code quality: trailing whitespace, unused imports, clippy warnings

- Fix trailing whitespace in kex.rs and s3.rs
- Add missing KexProposal import in kex_complete.rs
- Auto-fix clippy warnings across all crates
- All 153 tests pass

markbase-fuse/src/main.rs

@@ -30,7 +30,11 @@ fn main() -> Result<()> {
     let cli = Cli::parse();
 
     match cli.command {
-        Commands::Mount { user, dir, tree_type } => {
+        Commands::Mount {
+            user,
+            dir,
+            tree_type,
+        } => {
             mount_user(user, tree_type, dir)?;
         }
         Commands::Unmount { dir } => {
@@ -78,13 +82,15 @@ fn mount_user(user: String, tree_type: String, dir: PathBuf) -> Result<()> {
     println!("Press Ctrl+C to unmount...");
 
     let mut channel = session.new_channel()?;
-    
+
     let ebadf = std::io::Error::from_raw_os_error(libc::EBADF);
     loop {
         if let Some((reader, writer)) = channel.get_request()? {
             if let Err(e) = server.handle_message(reader, writer.into(), None, None) {
                 match e {
-                    fuse_backend_rs::Error::EncodeMessage(e) if e.kind() == std::io::ErrorKind::Other => {
+                    fuse_backend_rs::Error::EncodeMessage(e)
+                        if e.kind() == std::io::ErrorKind::Other =>
+                    {
                         break;
                     }
                     _ => {
@@ -112,4 +118,4 @@ fn unmount_user(dir: PathBuf) -> Result<()> {
 
     println!("Unmounted successfully");
     Ok(())
-}
+}