feat: add auto-prestige toggle via runestone shop upgrade

Adds a new Utility category to the prestige shop with the "Autonomous Ascension" upgrade (100 runestones). Once purchased, a toggle button appears in the shop that enables automatic prestige — the client RAF loop checks the threshold on each tick and fires the prestige API automatically using the current character name.

✨ This feature was implemented with help from Hikari~ 🌸

packages/types/src/interfaces/Prestige.ts

@@ -17,4 +17,6 @@ export interface PrestigeData {
   runestonesEssenceMultiplier?: number;
   /** Pre-computed multiplier from "crystals" runestone upgrades */
   runestonesCrystalMultiplier?: number;
+  /** Whether the auto-prestige feature is currently enabled (requires auto_prestige upgrade) */
+  autoPrestigeEnabled?: boolean;
 }

packages/types/src/interfaces/PrestigeUpgrade.ts

@@ -3,7 +3,8 @@ export type PrestigeUpgradeCategory =
   | "click"
   | "essence"
   | "crystals"
-  | "runestones";
+  | "runestones"
+  | "utility";
 
 export interface PrestigeUpgrade {
   id: string;