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

apps/api/src/index.ts

@@ -2,6 +2,7 @@ import { serve } from "@hono/node-server";
 import { Hono } from "hono";
 import { cors } from "hono/cors";
 import { logger } from "hono/logger";
+import { aboutRouter } from "./routes/about.js";
 import { authRouter } from "./routes/auth.js";
 import { bossRouter } from "./routes/boss.js";
 import { gameRouter } from "./routes/game.js";
@@ -20,6 +21,7 @@ app.use(
   }),
 );
 
+app.route("/about", aboutRouter);
 app.route("/auth", authRouter);
 app.route("/game", gameRouter);
 app.route("/boss", bossRouter);