getMarkDamageBonus

Power budget: the trigger rate for a mark is the mark's uptime, not the proc chance. The old 1.75x number was priced as if only 26.7% of hits landed on a marked target, but a 15 second mark refreshed by a 27% proc at hoe attack speed (4 swings/sec, ~60 rolls per mark window) is up on essentially every hit of a sustained fight. Allowing ~5% downtime for target switching and approach, the honest trigger rate is 0.95, so the level 50 bonus is +21% (E = 0.95 * 0.21 = 0.20). Hardcoded rather than read from config so every server runs the same numbers while the rebalance is being validated.