What happens during the header-processing stage when syncing a Kaspa node?

After pruning point proof processing finishes, your Kaspa node enters a header-processing stage where it downloads and verifies block headers from three days ago up to the current time. A block header is a compact summary of a block — it contains just enough information (like a timestamp and a fingerprint of the block's contents) for the node to build a skeleton of the DAG without downloading every full transaction right away. During this stage you can watch two progress indicators in your node's log: a line showing how many blocks and headers have been processed, along with the timestamp of the headers currently being worked on, and a separate line showing the overall percentage complete. Understanding this stage matters because it tells you your node is healthy and making forward progress — if you see the timestamp advancing toward the present, the sync is working as expected.