fix: ensure NFC normalization is applied consistently

- api/files.rs: NFC-normalize filename before sending to server in
  upload_file(). On macOS, local filenames may be NFD-encoded, which
  would cause the server to store them as NFD instead of NFC.

- commands/download.rs: replace direct to_lowercase() subfolder
  comparison with find_subfolder_by_name() helper, which already
  applies NFC normalization on both sides.

- commands/cp.rs, mv.rs: apply nfc() to s_basename (source path
  component from user input) for consistency with d_basename, so
  the no-op identity check and find_*() calls use normalized strings.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/api/files.rs

@@ -1,5 +1,6 @@
 use crate::connection::MDRSConnection;
 pub use crate::models::file::File;
+use unicode_normalization::UnicodeNormalization;
 
 #[derive(serde::Deserialize)]
 struct FileListResponse {
@@ -40,11 +41,12 @@ impl MDRSConnection {
         file_path: &str,
     ) -> Result<(), Box<dyn std::error::Error>> {
         use reqwest::multipart;
-        let file_name = std::path::Path::new(file_path)
+        let file_name: String = std::path::Path::new(file_path)
             .file_name()
             .unwrap()
             .to_string_lossy()
-            .to_string();
+            .nfc()
+            .collect();
         let file_bytes = tokio::fs::read(file_path).await?;
         let part = multipart::Part::bytes(file_bytes).file_name(file_name.clone());
         let form = multipart::Form::new()

src/commands/cp.rs

@@ -25,7 +25,8 @@ pub async fn cp(
     let lab_id = lab.id;
 
     // Split source path into parent directory and target name
-    let (s_dirname, s_basename) = split_path(&s_path);
+    let (s_dirname, s_basename_raw) = split_path(&s_path);
+    let s_basename = nfc(&s_basename_raw);
 
     // If dest ends with '/', treat it as a directory and preserve src basename
     let (d_dirname, d_basename_raw) = if dest_ends_with_slash {

src/commands/download.rs

@@ -1,6 +1,6 @@
 use crate::commands::shared::{
-    create_authenticated_conn, find_file_by_name, find_folder, find_lab_in_cache, load_cache_with_token_refresh,
-    parse_remote_path,
+    create_authenticated_conn, find_file_by_name, find_folder, find_lab_in_cache,
+    find_subfolder_by_name, load_cache_with_token_refresh, parse_remote_path,
 };
 use crate::connection::MDRSConnection;
 use futures::stream::{FuturesUnordered, StreamExt};
@@ -66,10 +66,7 @@ pub async fn download(
     }
 
     // Case 2: basename matches a sub-folder.
-    let subfolder = parent_folder
-        .sub_folders
-        .iter()
-        .find(|f| f.name.to_lowercase() == basename.to_lowercase());
+    let subfolder = find_subfolder_by_name(&parent_folder.sub_folders, &basename);
     if let Some(sub) = subfolder {
         if !recursive {
             return Err(format!("Cannot download `{}`: Is a folder.", r_path_clean).into());

src/commands/mv.rs

@@ -21,7 +21,8 @@ pub async fn mv(src_path: &str, dest_path: &str) -> Result<(), Box<dyn std::erro
     let lab_id = lab.id;
 
     // Split source path into parent directory and target name
-    let (s_dirname, s_basename) = split_path(&s_path);
+    let (s_dirname, s_basename_raw) = split_path(&s_path);
+    let s_basename = nfc(&s_basename_raw);
 
     // If dest ends with '/', treat it as a directory and preserve src basename
     let (d_dirname, d_basename_raw) = if dest_ends_with_slash {