fix: use rust blowfish instead of node

The JavaScript blowfish-node library had a critical bug where it would
sometimes return 2047 bytes instead of 2048 during decryption, causing
byte alignment issues that corrupted FLAC audio at specific intervals
(~every 32/82 seconds).

Changes:
- Add Rust dependencies: blowfish, md5, byteorder
- Implement new module in Rust with proper Blowfish CBC
- Add decryption Tauri command
- Update frontend to call Rust decryption instead of JavaScript
- Remove buggy JavaScript blowfish implementation
- Update decryption algorithm (6144-byte windows)

src-tauri/src/lib.rs

@@ -2,6 +2,7 @@ use tauri_plugin_sql::{Migration, MigrationKind};
 
 mod tagger;
 mod metadata;
+mod deezer_crypto;
 
 // Learn more about Tauri commands at https://tauri.app/develop/calling-rust/
 #[tauri::command]
@@ -26,6 +27,12 @@ fn read_audio_metadata(path: String) -> Result<metadata::AudioMetadata, String>
     metadata::read_audio_metadata(&path)
 }
 
+/// Decrypt Deezer track data
+#[tauri::command]
+fn decrypt_deezer_track(data: Vec<u8>, track_id: String) -> Result<Vec<u8>, String> {
+    Ok(deezer_crypto::decrypt_track(&data, &track_id))
+}
+
 #[cfg_attr(mobile, tauri::mobile_entry_point)]
 pub fn run() {
     let library_migrations = vec![Migration {
@@ -143,7 +150,12 @@ pub fn run() {
         .plugin(tauri_plugin_store::Builder::new().build())
         .plugin(tauri_plugin_dialog::init())
         .plugin(tauri_plugin_fs::init())
-        .invoke_handler(tauri::generate_handler![greet, tag_audio_file, read_audio_metadata])
+        .invoke_handler(tauri::generate_handler![
+            greet,
+            tag_audio_file,
+            read_audio_metadata,
+            decrypt_deezer_track
+        ])
         .run(tauri::generate_context!())
         .expect("error while running tauri application");
 }