Resolve which eligible Fate Mystery to spend a point from: auto-pick when exactly one is eligible, otherwise ask the player (pre-selecting the most-restricted point via preferredFateSource so flexible general points are preserved).
The eligible Fate Mystery logics (availableFateFor).
The chosen mystery, or undefined if the dialog was dismissed.
undefined
Resolve which eligible Fate Mystery to spend a point from: auto-pick when exactly one is eligible, otherwise ask the player (pre-selecting the most-restricted point via preferredFateSource so flexible general points are preserved).