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/health_stats.rs

@@ -1,14 +1,19 @@
-use axum::{Extension, Json, extract::{Path, State, Query}, http::StatusCode, response::IntoResponse};
-use mongodb::bson::oid::ObjectId;
-use serde::Deserialize;
-use crate::models::health_stats::HealthStatistic;
 use crate::auth::jwt::Claims;
 use crate::config::AppState;
+use crate::models::health_stats::HealthStatistic;
+use axum::{
+    extract::{Path, Query, State},
+    http::StatusCode,
+    response::IntoResponse,
+    Extension, Json,
+};
+use mongodb::bson::oid::ObjectId;
+use serde::Deserialize;
 
 #[derive(Debug, Deserialize)]
 pub struct CreateHealthStatRequest {
     pub stat_type: String,
-    pub value: serde_json::Value,  // Support complex values like blood pressure
+    pub value: serde_json::Value, // Support complex values like blood pressure
     pub unit: String,
     pub notes: Option<String>,
     pub recorded_at: Option<String>,
@@ -24,7 +29,7 @@ pub struct UpdateHealthStatRequest {
 #[derive(Debug, Deserialize)]
 pub struct HealthTrendsQuery {
     pub stat_type: String,
-    pub period: Option<String>,  // "7d", "30d", etc.
+    pub period: Option<String>, // "7d", "30d", etc.
 }
 
 pub async fn create_health_stat(
@@ -33,7 +38,7 @@ pub async fn create_health_stat(
     Json(req): Json<CreateHealthStatRequest>,
 ) -> impl IntoResponse {
     let repo = state.health_stats_repo.as_ref().unwrap();
-    
+
     // Convert complex value to f64 or store as string
     let value_num = match req.value {
         serde_json::Value::Number(n) => n.as_f64().unwrap_or(0.0),
@@ -41,9 +46,9 @@ pub async fn create_health_stat(
             // For complex objects like blood pressure, use a default
             0.0
         }
-        _ => 0.0
+        _ => 0.0,
     };
-    
+
     let stat = HealthStatistic {
         id: None,
         user_id: claims.sub.clone(),
@@ -61,7 +66,11 @@ pub async fn create_health_stat(
         Ok(created) => (StatusCode::CREATED, Json(created)).into_response(),
         Err(e) => {
             eprintln!("Error creating health stat: {:?}", e);
-            (StatusCode::INTERNAL_SERVER_ERROR, "Failed to create health stat").into_response()
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                "Failed to create health stat",
+            )
+                .into_response()
         }
     }
 }
@@ -75,7 +84,11 @@ pub async fn list_health_stats(
         Ok(stats) => (StatusCode::OK, Json(stats)).into_response(),
         Err(e) => {
             eprintln!("Error fetching health stats: {:?}", e);
-            (StatusCode::INTERNAL_SERVER_ERROR, "Failed to fetch health stats").into_response()
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                "Failed to fetch health stats",
+            )
+                .into_response()
         }
     }
 }
@@ -101,7 +114,11 @@ pub async fn get_health_stat(
         Ok(None) => (StatusCode::NOT_FOUND, "Health stat not found").into_response(),
         Err(e) => {
             eprintln!("Error fetching health stat: {:?}", e);
-            (StatusCode::INTERNAL_SERVER_ERROR, "Failed to fetch health stat").into_response()
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                "Failed to fetch health stat",
+            )
+                .into_response()
         }
     }
 }
@@ -121,7 +138,13 @@ pub async fn update_health_stat(
     let mut stat = match repo.find_by_id(&object_id).await {
         Ok(Some(s)) => s,
         Ok(None) => return (StatusCode::NOT_FOUND, "Health stat not found").into_response(),
-        Err(_) => return (StatusCode::INTERNAL_SERVER_ERROR, "Failed to fetch health stat").into_response(),
+        Err(_) => {
+            return (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                "Failed to fetch health stat",
+            )
+                .into_response()
+        }
     };
 
     if stat.user_id != claims.sub {
@@ -131,7 +154,7 @@ pub async fn update_health_stat(
     if let Some(value) = req.value {
         let value_num = match value {
             serde_json::Value::Number(n) => n.as_f64().unwrap_or(0.0),
-            _ => 0.0
+            _ => 0.0,
         };
         stat.value = value_num;
     }
@@ -145,7 +168,11 @@ pub async fn update_health_stat(
     match repo.update(&object_id, &stat).await {
         Ok(Some(updated)) => (StatusCode::OK, Json(updated)).into_response(),
         Ok(None) => (StatusCode::NOT_FOUND, "Failed to update").into_response(),
-        Err(_) => (StatusCode::INTERNAL_SERVER_ERROR, "Failed to update health stat").into_response(),
+        Err(_) => (
+            StatusCode::INTERNAL_SERVER_ERROR,
+            "Failed to update health stat",
+        )
+            .into_response(),
     }
 }
 
@@ -163,7 +190,13 @@ pub async fn delete_health_stat(
     let stat = match repo.find_by_id(&object_id).await {
         Ok(Some(s)) => s,
         Ok(None) => return (StatusCode::NOT_FOUND, "Health stat not found").into_response(),
-        Err(_) => return (StatusCode::INTERNAL_SERVER_ERROR, "Failed to fetch health stat").into_response(),
+        Err(_) => {
+            return (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                "Failed to fetch health stat",
+            )
+                .into_response()
+        }
     };
 
     if stat.user_id != claims.sub {
@@ -172,7 +205,11 @@ pub async fn delete_health_stat(
 
     match repo.delete(&object_id).await {
         Ok(true) => StatusCode::NO_CONTENT.into_response(),
-        _ => (StatusCode::INTERNAL_SERVER_ERROR, "Failed to delete health stat").into_response(),
+        _ => (
+            StatusCode::INTERNAL_SERVER_ERROR,
+            "Failed to delete health stat",
+        )
+            .into_response(),
     }
 }
 
@@ -189,21 +226,25 @@ pub async fn get_health_trends(
                 .into_iter()
                 .filter(|s| s.stat_type == query.stat_type)
                 .collect();
-            
+
             // Calculate basic trend statistics
             if filtered.is_empty() {
-                return (StatusCode::OK, Json(serde_json::json!({
-                    "stat_type": query.stat_type,
-                    "count": 0,
-                    "data": []
-                }))).into_response();
+                return (
+                    StatusCode::OK,
+                    Json(serde_json::json!({
+                        "stat_type": query.stat_type,
+                        "count": 0,
+                        "data": []
+                    })),
+                )
+                    .into_response();
             }
-            
+
             let values: Vec<f64> = filtered.iter().map(|s| s.value).collect();
             let avg = values.iter().sum::<f64>() / values.len() as f64;
             let min = values.iter().fold(f64::INFINITY, |a, &b| a.min(b));
             let max = values.iter().fold(f64::NEG_INFINITY, |a, &b| a.max(b));
-            
+
             let response = serde_json::json!({
                 "stat_type": query.stat_type,
                 "count": filtered.len(),
@@ -212,12 +253,16 @@ pub async fn get_health_trends(
                 "max": max,
                 "data": filtered
             });
-            
+
             (StatusCode::OK, Json(response)).into_response()
         }
         Err(e) => {
             eprintln!("Error fetching health trends: {:?}", e);
-            (StatusCode::INTERNAL_SERVER_ERROR, "Failed to fetch health trends").into_response()
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                "Failed to fetch health trends",
+            )
+                .into_response()
         }
     }
 }