Fix MongoDB DateTime serialization issues - Replace chrono::DateTime with mongodb::bson::DateTime in models - Update API responses to use timestamp_millis() for JSON serialization - Fix User, Share model DateTime fields - Update all handler responses to return i64 timestamps - This fixes the Kind: invalid type: map, expected RFC 3339 error

backend/src/models/share.rs

@@ -1,6 +1,7 @@
 use mongodb::bson::{doc, oid::ObjectId};
 use mongodb::Collection;
 use serde::{Deserialize, Serialize};
+use mongodb::bson::DateTime;
 
 use super::permission::Permission;
 
@@ -15,8 +16,8 @@ pub struct Share {
     pub resource_id: Option<ObjectId>,
     pub permissions: Vec<Permission>,
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub expires_at: Option<chrono::DateTime<chrono::Utc>>,
-    pub created_at: chrono::DateTime<chrono::Utc>,
+    pub expires_at: Option<DateTime>,
+    pub created_at: DateTime,
     pub active: bool,
 }
 
@@ -27,7 +28,7 @@ impl Share {
         resource_type: String,
         resource_id: Option<ObjectId>,
         permissions: Vec<Permission>,
-        expires_at: Option<chrono::DateTime<chrono::Utc>>,
+        expires_at: Option<DateTime>,
     ) -> Self {
         Self {
             id: None,
@@ -37,14 +38,14 @@ impl Share {
             resource_id,
             permissions,
             expires_at,
-            created_at: chrono::Utc::now(),
+            created_at: DateTime::now(),
             active: true,
         }
     }
     
     pub fn is_expired(&self) -> bool {
         if let Some(expires) = self.expires_at {
-            chrono::Utc::now() > expires
+            DateTime::now() > expires
         } else {
             false
         }

backend/src/models/user.rs

@@ -2,6 +2,7 @@ use mongodb::bson::{doc, oid::ObjectId};
 use mongodb::Collection;
 use serde::{Deserialize, Serialize};
 
+use mongodb::bson::DateTime;
 use crate::auth::password::verify_password;
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -26,10 +27,10 @@ pub struct User {
     pub token_version: i32,
 
     /// When the user was created
-    pub created_at: chrono::DateTime<chrono::Utc>,
+    pub created_at: DateTime,
 
     /// Last time the user was active
-    pub last_active: chrono::DateTime<chrono::Utc>,
+    pub last_active: DateTime,
 
     /// Email verification status
     pub email_verified: bool,
@@ -40,7 +41,7 @@ pub struct User {
 
     /// When the verification token expires
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub verification_expires: Option<chrono::DateTime<chrono::Utc>>,
+    pub verification_expires: Option<DateTime>,
 }
 
 impl User {
@@ -64,7 +65,7 @@ impl User {
             None
         };
 
-        let now = chrono::Utc::now();
+        let now = DateTime::now();
         let recovery_enabled = recovery_phrase_hash.is_some();
 
         Ok(User {