style: apply rustfmt to backend codebase

- Apply rustfmt to all Rust source files in backend/
- Fix trailing whitespace inconsistencies
- Standardize formatting across handlers, models, and services
- Improve code readability with consistent formatting

These changes are purely stylistic and do not affect functionality.
All CI checks now pass with proper formatting.

backend/src/main.rs

@@ -1,49 +1,49 @@
+mod auth;
 mod config;
 mod db;
-mod models;
-mod auth;
 mod handlers;
 mod middleware;
+mod models;
 mod security;
 mod services;
 
 use axum::{
-    routing::{get, post, put, delete},
+    routing::{delete, get, post, put},
     Router,
 };
-use tower::ServiceBuilder;
-use tower_http::{
-    cors::CorsLayer,
-    trace::TraceLayer,
-};
 use config::Config;
 use std::sync::Arc;
+use tower::ServiceBuilder;
+use tower_http::{cors::CorsLayer, trace::TraceLayer};
 
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
     eprintln!("NORMOGEN BACKEND STARTING...");
     eprintln!("Loading environment variables...");
-    
+
     match dotenv::dotenv() {
         Ok(path) => eprintln!("Loaded .env from: {:?}", path),
         Err(e) => eprintln!("No .env file found (this is OK in Docker): {}", e),
     }
-    
+
     eprintln!("Initializing logging...");
     tracing_subscriber::fmt::init();
 
     tracing::info!("Starting Normogen backend server");
-    
+
     // Load configuration
     let config = Config::from_env()?;
     eprintln!("Configuration loaded successfully");
-    
+
     // Connect to MongoDB
     tracing::info!("Connecting to MongoDB at {}", config.database.uri);
     eprintln!("Connecting to MongoDB...");
     let db = match db::MongoDb::new(&config.database.uri, &config.database.database).await {
         Ok(db) => {
-            tracing::info!("Connected to MongoDB database: {}", config.database.database);
+            tracing::info!(
+                "Connected to MongoDB database: {}",
+                config.database.database
+            );
             eprintln!("MongoDB connection successful");
             db
         }
@@ -52,7 +52,7 @@ async fn main() -> anyhow::Result<()> {
             return Err(e);
         }
     };
-    
+
     match db.health_check().await {
         Ok(_) => {
             tracing::info!("MongoDB health check: OK");
@@ -73,13 +73,13 @@ async fn main() -> anyhow::Result<()> {
     // Initialize security services (Phase 2.6)
     let audit_logger = security::AuditLogger::new(&database);
     let session_manager = security::SessionManager::new(&database);
-    
+
     // Create account lockout service with reasonable defaults
     let user_collection = database.collection("users");
     let account_lockout = security::AccountLockout::new(
         user_collection,
-        5,  // max_attempts
-        15, // base_duration_minutes
+        5,    // max_attempts
+        15,   // base_duration_minutes
         1440, // max_duration_minutes (24 hours)
     );
 
@@ -102,17 +102,23 @@ async fn main() -> anyhow::Result<()> {
         mongo_client: None,
         interaction_service: Some(interaction_service),
     };
-    
+
     eprintln!("Building router with security middleware...");
-    
+
     // Build public routes (no auth required)
     let public_routes = Router::new()
-        .route("/health", get(handlers::health_check).head(handlers::health_check))
+        .route(
+            "/health",
+            get(handlers::health_check).head(handlers::health_check),
+        )
         .route("/ready", get(handlers::ready_check))
         .route("/api/auth/register", post(handlers::register))
         .route("/api/auth/login", post(handlers::login))
-        .route("/api/auth/recover-password", post(handlers::recover_password));
-    
+        .route(
+            "/api/auth/recover-password",
+            post(handlers::recover_password),
+        );
+
     // Build protected routes (auth required)
     let protected_routes = Router::new()
         // User profile management
@@ -163,7 +169,7 @@ async fn main() -> anyhow::Result<()> {
             state.clone(),
             middleware::jwt_auth_middleware
         ));
-    
+
     let app = public_routes
         .merge(protected_routes)
         .with_state(state)
@@ -186,8 +192,8 @@ async fn main() -> anyhow::Result<()> {
     let listener = tokio::net::TcpListener::bind(&addr).await?;
     eprintln!("Server listening on {}", &addr);
     tracing::info!("Server listening on {}", &addr);
-    
+
     axum::serve(listener, app).await?;
-    
+
     Ok(())
 }