feat: content expansion, prestige shop, and offline earnings improvements

- Expand content to 18 zones, 72 bosses, 95 quests, 32 adventurer tiers
- Add prestige shop with 24 runestone upgrades across 5 categories
- Add PrestigeUpgrade type, data files, API routes, and frontend panel
- Fix offline earnings to include equipment and runestone multipliers
- Add offline essence calculation alongside offline gold
- Update OfflineModal to display both gold and essence earned
- Add IDEAS.md for tracking planned features

packages/types/src/index.ts

@@ -10,6 +10,8 @@ export type {
   AuthResponse,
   BossChallengeRequest,
   BossChallengeResponse,
+  BuyPrestigeUpgradeRequest,
+  BuyPrestigeUpgradeResponse,
   LoadResponse,
   PrestigeRequest,
   PrestigeResponse,
@@ -29,6 +31,10 @@ export type {
 export type { GameState } from "./interfaces/GameState.js";
 export type { Player } from "./interfaces/Player.js";
 export type { PrestigeData } from "./interfaces/Prestige.js";
+export type {
+  PrestigeUpgrade,
+  PrestigeUpgradeCategory,
+} from "./interfaces/PrestigeUpgrade.js";
 export type {
   Quest,
   QuestReward,

packages/types/src/interfaces/Api.ts

@@ -24,6 +24,8 @@ export interface LoadResponse {
   state: GameState;
   /** Offline gold earned since last save (server-calculated) */
   offlineGold: number;
+  /** Offline essence earned since last save (server-calculated) */
+  offlineEssence: number;
   /** Seconds the player was offline (capped at 8 hours) */
   offlineSeconds: number;
   /** HMAC-SHA256 signature of the loaded state — store and include in next save request */
@@ -72,6 +74,19 @@ export interface PrestigeResponse {
   newPrestigeCount: number;
 }
 
+export interface BuyPrestigeUpgradeRequest {
+  upgradeId: string;
+}
+
+export interface BuyPrestigeUpgradeResponse {
+  runestonesRemaining: number;
+  purchasedUpgradeIds: string[];
+  runestonesIncomeMultiplier: number;
+  runestonesClickMultiplier: number;
+  runestonesEssenceMultiplier: number;
+  runestonesCrystalMultiplier: number;
+}
+
 export interface PublicProfileResponse {
   characterName: string;
   username: string;

packages/types/src/interfaces/Prestige.ts

@@ -9,4 +9,12 @@ export interface PrestigeData {
   purchasedUpgradeIds: string[];
   /** Unix timestamp of last prestige */
   lastPrestigedAt?: number;
+  /** Pre-computed multiplier from "income" runestone upgrades */
+  runestonesIncomeMultiplier?: number;
+  /** Pre-computed multiplier from "click" runestone upgrades */
+  runestonesClickMultiplier?: number;
+  /** Pre-computed multiplier from "essence" runestone upgrades */
+  runestonesEssenceMultiplier?: number;
+  /** Pre-computed multiplier from "crystals" runestone upgrades */
+  runestonesCrystalMultiplier?: number;
 }

packages/types/src/interfaces/PrestigeUpgrade.ts

@@ -0,0 +1,16 @@
+export type PrestigeUpgradeCategory =
+  | "income"
+  | "click"
+  | "essence"
+  | "crystals"
+  | "runestones";
+
+export interface PrestigeUpgrade {
+  id: string;
+  name: string;
+  description: string;
+  category: PrestigeUpgradeCategory;
+  runestonesCost: number;
+  /** Multiplier applied when this upgrade is purchased */
+  multiplier: number;
+}

packages/types/src/interfaces/Quest.ts

@@ -23,4 +23,6 @@ export interface Quest {
   prerequisiteIds: string[];
   /** Zone this quest belongs to */
   zoneId: string;
+  /** Minimum party combat power required to start this quest */
+  combatPowerRequired?: number;
 }