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/user_dto.rs

@@ -1,6 +1,6 @@
-use serde::{Serialize, Deserialize};
-use chrono::{DateTime, Utc};
 use crate::domain::entities::user::User;
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
 
 #[derive(Debug, Serialize, Deserialize)]
 pub struct UserDto {
@@ -117,4 +117,4 @@ pub struct OidcUserInfoDto {
     pub email: Option<String>,
     pub name: Option<String>,
     pub groups: Vec<String>,
-}
+}