feat: add codex / lore book with 364 entries

Implements a full in-game Codex panel that tracks lore discovery across
seven categories: bosses (72), quests (95), zones (18), equipment (65),
adventurer tiers (32), upgrades (57), and prestige upgrades (25).

Lore entries unlock automatically as players progress — existing
completions are retroactively and silently added on first load. New
discoveries trigger a toast notification and badge counter on the
Codex tab.

packages/types/src/index.ts

@@ -1,3 +1,4 @@
+export type { CodexEntry, CodexState } from "./interfaces/Codex.js";
 export type {
   Achievement,
   AchievementCondition,

packages/types/src/interfaces/Codex.ts

@@ -0,0 +1,12 @@
+export interface CodexEntry {
+  id: string;
+  title: string;
+  content: string;
+  sourceType: "boss" | "quest" | "equipment" | "adventurer" | "upgrade" | "prestige" | "zone";
+  sourceId: string;
+  zoneId: string;
+}
+
+export interface CodexState {
+  unlockedEntryIds: string[];
+}

packages/types/src/interfaces/GameState.ts

@@ -1,6 +1,7 @@
 import type { Achievement } from "./Achievement.js";
 import type { Adventurer } from "./Adventurer.js";
 import type { Boss } from "./Boss.js";
+import type { CodexState } from "./Codex.js";
 import type { DailyChallengeState } from "./DailyChallenge.js";
 import type { Equipment } from "./Equipment.js";
 import type { Player } from "./Player.js";
@@ -27,4 +28,6 @@ export interface GameState {
   lastTickAt: number;
   /** Daily challenge progress — optional for backwards compatibility with old saves */
   dailyChallenges?: DailyChallengeState;
+  /** Lore codex unlock state — optional for backwards compatibility with old saves */
+  codex?: CodexState;
 }