Zender: BLAKE2b Hard Fork Activates

Zender executed its flag-day hard fork at block 961640, switching from SHA256d to BLAKE2b proof of work with an initial target near 218 TH/s while keeping the 2,016-block difficulty adjustment intact. The chain now enforces a mandatory 164-byte version-2 header that commits to transaction count, adds ASIC profiles, and includes an optional XOR key for block-withholding defense. Temporary RDTS limits cap blocks at 800,000 weight units until September 2027 and restrict Taproot trees and certain opcodes, grandfathering pre-fork coins. These Bitcoin hard fork changes also introduce unified sighash for replay protection across legacy, SegWit and Taproot inputs.