migrate from PyQt6 to PySide6, remove unneeded dependencies

src/backend/admin_console.py

@@ -44,6 +44,19 @@ class AdminCommands:
         hashed_password = self.hash_password("admin")
         self.db.createUser("admin", salt + hashed_password, "admin", salt)
 
+    def create_user(self, username: str, password: str, role: str = "user"):
+        """Create a new user in the database.
+
+        Args:
+            username (str): the username of the user to be created.
+            password (str): the password of the user to be created.
+            role (str, optional): the role of the user to be created. Defaults to "user".
+        """
+        hashed_password, salt = self.create_password(password)
+        self.db.createUser(
+            user=username, password=salt + hashed_password, role=role, salt=salt
+        )
+
     def hash_password(self, password: str) -> str:
         """Hash a password using SHA256.