Access mettle, flourish outside runs; adjust mettle's mechanism

[TimTheMelon]

Mettles & Flourish should be accessed outside runs. This eliminates the redundancy of having two places (in run and outside run) to permanently upgrading grifter, reducing potential confusion, and creates a smoother, more immersive grifting experience.

Mettle should distinguish itself from perk. Rather than definitive upgrades like perks, mettles could work based on CHANCES. For example, instead of permanently upgrading a grifter's health, the mettle could give players "0.5%(~1%) chance to get an extra option to increase maximum health by 1 when picking battle cards after battle.". This would make players feel they would still have to play well to have a successful run (instead of playing more, grinding), with the mettle system as a slight aid depending on luck.