Register an algorithm implementation under a stage contract

Usage

register_strategy(contract, name, constructor, replace = FALSE, reason = NULL)

contract: character contract class name (e.g. "Decomposer")
name: character unique implementation name
constructor: R closure with signature function(params_list) returning a contract-class instance. Primitive functions are unsupported because their implementation state cannot satisfy the registry fingerprint contract.
replace: logical; whether to deliberately replace a different constructor already registered under the same key. Re-registering a fingerprint-equivalent constructor, with the same code and behavior-relevant captured state, is an idempotent no-op.
reason: non-empty character rationale required when replace is TRUE; retained in registry provenance.

invisible NULL