Proof-of-work registration

Registering as a miner normally costs TAO. Proof-of-work registration is a second way in, on subnets where it is turned on.

Instead of paying a fee, a miner solves a computational challenge with its own hardware, using a GPU if it has one and a CPU if not. The solution is the entry ticket, and no TAO is spent upfront.

Like the TAO price, the challenge gets harder when many people try to join at once. Paying and solving are tracked separately, so a rush on one route does not make the other more expensive.

Proof of work does not skip the usual rules. Pruning, the immunity period and the limit on registrations per block all still apply.

It also opens the door to miners who have compute but no TAO, including autonomous AI agents.