Function append_supersede 

pub fn append_supersede<T>(
    records: &mut Vec<BitemporalRecord<T>>,
    new_record: BitemporalRecord<T>,
) -> Result<Vec<SupersessionReceipt>, BitemporalError>
where
    T: Clone,

Append a new record and mark prior versions as superseded.

This is the core append-supersede operation:

• A new row is inserted with the given valid_time and a new recorded_time
• Any prior rows for the same record ID are marked as superseded

Returns a SupersessionReceipt for each superseded prior record.

Arguments

• records — mutable slice of existing records (simulating a database table)
• new_record — the new record to append

Returns

Vector of SupersessionReceipt for each superseded prior version.