Improve error handling, logging, and security in authentication services and utilities

- Refactored `create_user` and `change_password` methods to add transaction rollback on failures and enhanced logging for error contexts.
- Updated security utilities to use constant-time comparison (`hmac.compare_digest`) to mitigate timing attacks.
- Adjusted API responses in registration and password reset flows for better security and user experience.
- Added session invalidation after password resets to enhance account security.

backend/app/api/routes/organizations.py

@@ -62,7 +62,7 @@ async def get_my_organizations(
         # Add member count and role to each organization
         orgs_with_data = []
         for org in orgs:
-            role = organization_crud.get_user_role_in_org(
+            role = await organization_crud.get_user_role_in_org(
                 db,
                 user_id=current_user.id,
                 organization_id=org.id