Deduct mana conversion rates from raw regen (Bug 10)

- Added getTotalAttunementConversionDrain function to calculate total conversion drain
- Updated computeRegen to include attunement regen bonus
- Added computeEffectiveRegenForDisplay function for UI display
- Added conversionDrains to GameState to track per-attunement drain
- Updated tick function to track and persist conversion drains
- Build passes successfully

src/lib/game/data/attunements.ts

@@ -101,6 +101,19 @@ export function getTotalAttunementRegen(attunements: Record<string, { active: bo
     }, 0);
 }
 
+// Helper function to calculate total conversion drain from all active attunements (per hour)
+export function getTotalAttunementConversionDrain(attunements: Record<string, { active: boolean; level: number; experience: number }>): number {
+  return Object.entries(attunements)
+    .filter(([, state]) => state.active)
+    .reduce((total, [id, state]) => {
+      const def = ATTUNEMENTS_DEF[id];
+      if (!def || def.conversionRate <= 0) return total;
+      // Use the same level scaling as getAttunementConversionRate
+      const scaledRate = getAttunementConversionRate(id, state.level || 1);
+      return total + scaledRate;
+    }, 0);
+}
+
 // Get conversion rate with level scaling
 export function getAttunementConversionRate(attunementId: string, level: number): number {
   const def = ATTUNEMENTS_DEF[attunementId];