Remove the necessity of a Bulldozer class

The `Bulldozer` is essentially a lighter `Miner`, with some guardrails and a method to reduce the local-measures memoization structures coming from different `Bulldozers` together.

Consider whether it is necessary or if the code could be considerably simplified.

Locate the `Bulldozer` and `Miner` definitions and all references in the source tree, then trace where Bulldozer-specific guardrails or memoization-merging behavior is used. Compare those paths with plain `Miner` usage to determine whether the class is still required. Check the existing tests or examples covering mining workflows to establish expected behavior before refactoring. Done when tests pass and equivalent behavior remains after removing or collapsing the `Bulldozer` abstraction.

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