Introduce a configurable sort priority for Set A and Set B in the
`outliers` subcommand, replacing the single-criterion "Result desc".
New CLI flag:
--sort ABBR_LIST comma-separated metric abbreviations
(default: R,EP,PF,RF,SR,P,DD,C,T)
Abbreviations: R=Result, P=Profit, EP=Expected Payoff, PF=Profit Factor,
RF=Recovery Factor, SR=Sharpe Ratio, C=Custom, DD=Equity DD %, T=Trades.
Equity DD % sorts ascending (lower is better); all others descending.
Unmentioned abbreviations are appended at default order.