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/handlers/medications.rs

@@ -1,14 +1,17 @@
 use axum::{
-    extract::{Path, Query, State, Extension, Json},
+    extract::{Extension, Json, Path, Query, State},
     http::StatusCode,
 };
 use mongodb::bson::oid::ObjectId;
 use std::time::SystemTime;
 
 use crate::{
-    models::medication::{Medication, MedicationRepository, CreateMedicationRequest, UpdateMedicationRequest, LogDoseRequest},
-    auth::jwt::Claims,  // Fixed: import from auth::jwt instead of handlers::auth
+    auth::jwt::Claims, // Fixed: import from auth::jwt instead of handlers::auth
     config::AppState,
+    models::medication::{
+        CreateMedicationRequest, LogDoseRequest, Medication, MedicationRepository,
+        UpdateMedicationRequest,
+    },
 };
 
 #[derive(serde::Deserialize)]
@@ -25,7 +28,7 @@ pub async fn create_medication(
 ) -> Result<Json<Medication>, StatusCode> {
     let database = state.db.get_database();
     let repo = MedicationRepository::new(database.collection("medications"));
-    
+
     let now = SystemTime::now();
     let medication_id = uuid::Uuid::new_v4().to_string();
 
@@ -59,12 +62,15 @@ pub async fn create_medication(
         user_id: claims.sub,
         profile_id: req.profile_id.clone(),
         medication_data,
-        reminders: req.reminder_times.unwrap_or_default().into_iter().map(|time| {
-            crate::models::medication::MedicationReminder {
+        reminders: req
+            .reminder_times
+            .unwrap_or_default()
+            .into_iter()
+            .map(|time| crate::models::medication::MedicationReminder {
                 reminder_id: uuid::Uuid::new_v4().to_string(),
                 scheduled_time: time,
-            }
-        }).collect(),
+            })
+            .collect(),
         created_at: now.into(),
         updated_at: now.into(),
         pill_identification: req.pill_identification, // Phase 2.8
@@ -83,13 +89,10 @@ pub async fn list_medications(
 ) -> Result<Json<Vec<Medication>>, StatusCode> {
     let database = state.db.get_database();
     let repo = MedicationRepository::new(database.collection("medications"));
-    
+
     let _limit = query.limit.unwrap_or(100);
 
-    match repo
-        .find_by_user(&claims.sub)
-        .await
-    {
+    match repo.find_by_user(&claims.sub).await {
         Ok(medications) => Ok(Json(medications)),
         Err(_) => Err(StatusCode::INTERNAL_SERVER_ERROR),
     }
@@ -102,7 +105,7 @@ pub async fn get_medication(
 ) -> Result<Json<Medication>, StatusCode> {
     let database = state.db.get_database();
     let repo = MedicationRepository::new(database.collection("medications"));
-    
+
     match ObjectId::parse_str(&id) {
         Ok(oid) => match repo.find_by_id(&oid).await {
             Ok(Some(medication)) => Ok(Json(medication)),
@@ -121,7 +124,7 @@ pub async fn update_medication(
 ) -> Result<Json<Medication>, StatusCode> {
     let database = state.db.get_database();
     let repo = MedicationRepository::new(database.collection("medications"));
-    
+
     match ObjectId::parse_str(&id) {
         Ok(oid) => match repo.update(&oid, req).await {
             Ok(Some(medication)) => Ok(Json(medication)),
@@ -139,7 +142,7 @@ pub async fn delete_medication(
 ) -> Result<StatusCode, StatusCode> {
     let database = state.db.get_database();
     let repo = MedicationRepository::new(database.collection("medications"));
-    
+
     match ObjectId::parse_str(&id) {
         Ok(oid) => match repo.delete(&oid).await {
             Ok(true) => Ok(StatusCode::NO_CONTENT),
@@ -157,9 +160,9 @@ pub async fn log_dose(
     Json(req): Json<LogDoseRequest>,
 ) -> Result<StatusCode, StatusCode> {
     let database = state.db.get_database();
-    
+
     let now = SystemTime::now();
-    
+
     let dose = crate::models::medication::MedicationDose {
         id: None,
         medication_id: id.clone(),
@@ -169,8 +172,12 @@ pub async fn log_dose(
         taken: req.taken.unwrap_or(true),
         notes: req.notes,
     };
-    
-    match database.collection("medication_doses").insert_one(dose.clone(), None).await {
+
+    match database
+        .collection("medication_doses")
+        .insert_one(dose.clone(), None)
+        .await
+    {
         Ok(_) => Ok(StatusCode::CREATED),
         Err(_) => Err(StatusCode::INTERNAL_SERVER_ERROR),
     }
@@ -183,7 +190,7 @@ pub async fn get_adherence(
 ) -> Result<Json<crate::models::medication::AdherenceStats>, StatusCode> {
     let database = state.db.get_database();
     let repo = MedicationRepository::new(database.collection("medications"));
-    
+
     match repo.calculate_adherence(&id, 30).await {
         Ok(stats) => Ok(Json(stats)),
         Err(_) => Err(StatusCode::INTERNAL_SERVER_ERROR),