feat: initial elysium idle game prototype

Sets up the full monorepo with pnpm workspaces. Includes shared types
package, Hono API with Discord OAuth/JWT auth, Prisma v6 + MongoDB
Atlas, and React + Vite frontend with game loop, five tabs, and
Discord-linked save/load.

apps/web/src/api/client.ts

@@ -0,0 +1,81 @@
+import type {
+  AuthResponse,
+  BossDamageRequest,
+  BossDamageResponse,
+  LoadResponse,
+  PrestigeRequest,
+  PrestigeResponse,
+  PublicProfileResponse,
+  SaveRequest,
+  SaveResponse,
+} from "@elysium/types";
+
+const BASE_URL = "/api";
+
+const getToken = (): string | null => localStorage.getItem("elysium_token");
+
+const headers = (): Record<string, string> => {
+  const token = getToken();
+  return {
+    "Content-Type": "application/json",
+    ...(token ? { Authorization: `Bearer ${token}` } : {}),
+  };
+};
+
+const request = async <T>(
+  path: string,
+  options?: RequestInit,
+): Promise<T> => {
+  const response = await fetch(`${BASE_URL}${path}`, {
+    ...options,
+    headers: { ...headers(), ...options?.headers },
+  });
+
+  if (!response.ok) {
+    const error = (await response.json().catch(() => ({ error: "Unknown error" }))) as {
+      error: string;
+    };
+    throw new Error(error.error);
+  }
+
+  return response.json() as Promise<T>;
+};
+
+export const getAuthUrl = async (): Promise<string> => {
+  const data = await request<{ url: string }>("/auth/url");
+  return data.url;
+};
+
+export const handleAuthCallback = async (code: string): Promise<AuthResponse> => {
+  const data = await request<AuthResponse>(`/auth/callback?code=${code}`);
+  localStorage.setItem("elysium_token", data.token);
+  return data;
+};
+
+export const loadGame = async (): Promise<LoadResponse> =>
+  request<LoadResponse>("/game/load");
+
+export const saveGame = async (body: SaveRequest): Promise<SaveResponse> =>
+  request<SaveResponse>("/game/save", {
+    method: "POST",
+    body: JSON.stringify(body),
+  });
+
+export const dealBossDamage = async (
+  body: BossDamageRequest,
+): Promise<BossDamageResponse> =>
+  request<BossDamageResponse>("/boss/damage", {
+    method: "POST",
+    body: JSON.stringify(body),
+  });
+
+export const prestige = async (body: PrestigeRequest): Promise<PrestigeResponse> =>
+  request<PrestigeResponse>("/prestige", {
+    method: "POST",
+    body: JSON.stringify(body),
+  });
+
+export const getPublicProfile = async (
+  discordId: string,
+): Promise<PublicProfileResponse> =>
+  request<PublicProfileResponse>(`/profile/${discordId}`);