feat: add about page with versions, changelog, and how-to-play

- New GET /about API endpoint caches Gitea releases for 5 minutes
- AboutPanel displays client version (via Vite define), API version, collapsible changelog, and How to Play guide
- GiteaRelease and AboutResponse types added to shared package

packages/types/src/index.ts

@@ -6,12 +6,14 @@ export type {
 } from "./interfaces/Achievement.js";
 export type { Adventurer, AdventurerClass } from "./interfaces/Adventurer.js";
 export type {
+  AboutResponse,
   ApiError,
   AuthResponse,
   BossChallengeRequest,
   BossChallengeResponse,
   BuyPrestigeUpgradeRequest,
   BuyPrestigeUpgradeResponse,
+  GiteaRelease,
   LoadResponse,
   PrestigeRequest,
   PrestigeResponse,

packages/types/src/interfaces/Api.ts

@@ -119,5 +119,17 @@ export interface ApiError {
   error: string;
 }
 
+export interface GiteaRelease {
+  tag_name: string;
+  name: string;
+  body: string;
+  published_at: string;
+}
+
+export interface AboutResponse {
+  apiVersion: string;
+  releases: GiteaRelease[];
+}
+
 // Re-export for convenience
 export type { ProfileSettings };