Implement a simple linked list data structure.
Create a singly linked list supporting append, prepend, and deletion of the first matching value. The list must preserve insertion order and support conversion to a Python list.
Use implement_linked_list(operations), where each operation is a dictionary such as {"op": "append", "value": 4} or {"op": "delete", "value": 4}. Return the final list of values. Deleting a missing value has no effect.
def implement_linked_list(operations):