feat: add equipment set bonuses and boss bounty runestones

- Define EquipmentSet type + computeSetBonuses utility in packages/types
- Add setId field to Equipment type and assign sets to 27 equipment items
- Create 9 named equipment sets (Iron Vanguard → Eternal Throne) with 2pc/3pc bonuses
- Apply set combat multiplier in boss route
- Apply set gold/click multipliers in tick engine and click handler
- Include set bonuses in anti-cheat delta validation
- Show active set bonus strip + set badge per card in EquipmentPanel
- Add boss first-kill bounty runestones (scaling 1–10 per boss tier)
- Update AboutPanel and IDEAS.md

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

@@ -28,8 +28,8 @@ const HOW_TO_PLAY = [
     body: "New zones unlock when you defeat the final boss AND complete the final quest of the previous zone. Each zone contains new bosses and quests with progressively greater rewards.",
   },
   {
-    title: "🗡️ Equipment",
-    body: "Earn equipment from boss drops and quest rewards. Each piece of equipment provides bonuses to gold income, click power, or adventurer output. Rarer equipment provides stronger bonuses.",
+    title: "🗡️ Equipment & Sets",
+    body: "Earn equipment from boss drops and quest rewards. Each piece provides bonuses to gold income, click power, or combat. Rarer equipment provides stronger bonuses. Equip matching set pieces (2 or 3 of a named set) to unlock escalating set bonuses shown at the top of the Equipment panel.",
   },
   {
     title: "⭐ Prestige",