chore: clarify equipment combat bonus applies to boss fights only (#83)

## Summary

Resolves player confusion about equipment combat bonuses not affecting quest combat power. The behaviour is by design — combat multipliers only apply to boss DPS — but this was never communicated anywhere.

- **Equipment bonus labels** now read `+X% Boss Combat` instead of `+X% Combat` (both individual items and set bonuses)
- **About panel** — both equipment entries updated to explicitly state that combat bonuses only affect boss fights, and that quest combat power is determined solely by adventurers

No game logic changed.

Closes #81

✨ This PR was created with help from Hikari~ 🌸

Reviewed-on: #83
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

apps/web/src/components/game/equipmentPanel.tsx

@@ -31,7 +31,7 @@ const bonusDescription = (item: Equipment): string => {
   const parts: Array<string> = [];
   if (item.bonus.combatMultiplier !== undefined) {
     const pct = Math.round((item.bonus.combatMultiplier - 1) * 100);
-    parts.push(`+${String(pct)}% Combat`);
+    parts.push(`+${String(pct)}% Boss Combat`);
   }
   if (item.bonus.goldMultiplier !== undefined) {
     const pct = Math.round((item.bonus.goldMultiplier - 1) * 100);
@@ -276,7 +276,7 @@ const EquipmentPanel = (): JSX.Element => {
         }
         if (bonus.combatMultiplier !== undefined) {
           const pct = Math.round((bonus.combatMultiplier - 1) * 100);
-          parts.push(`+${String(pct)}% Combat (${String(threshold)}pc)`);
+          parts.push(`+${String(pct)}% Boss Combat (${String(threshold)}pc)`);
         }
         if (bonus.clickMultiplier !== undefined) {
           const pct = Math.round((bonus.clickMultiplier - 1) * 100);