Add hospital revival, Robbie bandit, MW/shop fixes, float64 scoring

- St. Guildmore's Memorial Hospital: !hospital command with Nurse Joy,
  procedural itemized billing, same-day revival, 6-hour dead timer,
  hospital ad after death, 2-hour nudge follow-up
- Robbie the Friendly Bandit: automated inventory cleaner, random daily
  visits (8-21 UTC, 40% chance), collects sub-tier gear at €50/item,
  donates to community pot, drops Get Out of Medical Debt Free card
- Fix MW auto-equip: T1 MW no longer replaces better equipped gear
- Fix shop MW block: allow purchasing upgrades over lower-tier MW
- Float64 equipment scoring: advEffectiveTier and advEquipmentScore
  return float64, no mid-calculation truncation (MW 1.25x, Arena 1.5x)
- Fix markdown rendering: convert *asterisk* to _underscore_ italics
  across all flavor text files (shop, blacksmith, rival, hospital)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/plugin/adventure_activities.go

@@ -426,7 +426,7 @@ type advProbabilities struct {
 }
 
 func calculateAdvProbabilities(char *AdventureCharacter, equip map[EquipmentSlot]*AdvEquipment, loc *AdvLocation, bonuses *AdvBonusSummary, inPenaltyZone bool) advProbabilities {
-	eqScore := float64(advEquipmentScore(equip))
+	eqScore := advEquipmentScore(equip)
 	skillLevel := float64(advEffectiveSkill(char, loc.Activity, bonuses))
 
 	deathPct := loc.BaseDeathPct - (eqScore * 0.8) - (skillLevel * 0.5) + bonuses.DeathModifier