Stateless f64 x f64 -> bool, out = (a > b), STRICT: a == b emits false (a close
exactly equal to the previous bar's high is not a breakout). Computes
breakout = close15 > prevHigh15 in the session-breakout strategy. First
bool-emitting f64 comparator; the operator is topology (relational siblings are
separate types, never a swept param). Build-step 2 of milestone 'Strategy node
vocabulary I'.
closes#85
