style: apply cargo fmt to entire codebase

Standardize code formatting across all 173 Rust source files
using rustfmt. No functional changes - purely cosmetic.

This establishes a consistent code style baseline for the
project going forward.

src/application/dtos/favorites_dto.rs

@@ -1,21 +1,21 @@
-use serde::{Deserialize, Serialize};
 use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
 
 /// DTO for favorites item
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct FavoriteItemDto {
     /// Unique identifier for the favorite entry
     pub id: String,
-    
+
     /// User ID who owns this favorite
     pub user_id: String,
-    
+
     /// ID of the favorited item (file or folder)
     pub item_id: String,
-    
+
     /// Type of the item ('file' or 'folder')
     pub item_type: String,
-    
+
     /// When the item was added to favorites
     pub created_at: DateTime<Utc>,
-}
+}