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-core/src/vfs/util.rs

@@ -7,7 +7,9 @@ use std::path::Path;
 pub fn map_io_error(path: &Path, e: std::io::Error) -> VfsError {
     match e.kind() {
         std::io::ErrorKind::NotFound => VfsError::NotFound(path.display().to_string()),
-        std::io::ErrorKind::PermissionDenied => VfsError::PermissionDenied(path.display().to_string()),
+        std::io::ErrorKind::PermissionDenied => {
+            VfsError::PermissionDenied(path.display().to_string())
+        }
         std::io::ErrorKind::AlreadyExists => VfsError::AlreadyExists(path.display().to_string()),
         std::io::ErrorKind::DirectoryNotEmpty => VfsError::NotEmpty(path.display().to_string()),
         std::io::ErrorKind::NotADirectory => VfsError::NotADirectory(path.display().to_string()),
@@ -65,13 +67,7 @@ pub fn build_long_name(stat: &VfsStat, name: &str) -> String {
 
     format!(
         "{}{} {} {} {} {} {} {}",
-        file_type, perms,
-        link_count,
-        stat.uid,
-        stat.gid,
-        size,
-        mtime,
-        name
+        file_type, perms, link_count, stat.uid, stat.gid, size, mtime, name
     )
 }