v0.2.6

• portfolio(id, members, key, options) starts a list of members on an input and gives the output of the best member. The result is also a member.
• selectBest(candidates, levels) is the pick rule. It keeps each candidate that is not worse than the best value of a level, so the minEffect ties do not drift.
• The level 0 of a portfolio is the count of hard breaks. A member that throws, or gives a value that is not finite, gets the status error.
• The options maxMembers and budgetMs cut the members. A cut by the time limit makes the trace not deterministic.
• pickMoves(trace) gives the move pick (the trace measure move.pick of a record), so exercised reads the effect of a pick. docs/PORTFOLIO.md tells the rules.