pub const HEAD_BLOCK: &'static [u8] = b"LOCAL_HEAD_BLOCK";Expand description
Highest known longest-chain head used for fork detection.
If a new block extends past HEAD_BLOCK,
it is treated as longest-chain extension.
If another block appears at the same height or lower, it is treated as a sibling fork.
Sibling fork detection is best-effort:
a lower block may still be the head of its own valid fork, but it is treated as a sibling branch of the nearest known path.
This intentionally favors fewer branch creations and reduced storage growth over perfect historical fork reconstruction.