Function apply 

pub fn apply(
    data: &mut Vec<u8>,
    timestamp_ns: u64,
    ts_delta: i64,
    origlen: u32,
    opts: &TransformOptions,
) -> (u64, u32, u32)

Apply all configured transformations to one captured packet.

Mutates data in place and returns (new_timestamp_ns, new_caplen, new_origlen).

• ts_delta — pre-computed nanosecond shift; 0 disables timestamp shifting.
• origlen — original wire length from the PCAP record header.