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/api/vitest.config.ts

@@ -0,0 +1,18 @@
+import { defineConfig } from "vitest/config";
+
+export default defineConfig({
+  test: {
+    coverage: {
+      provider: "v8",
+      include: ["src/**/*.ts"],
+      exclude: ["src/types/**/*.ts"],
+      thresholds: {
+        statements: 100,
+        branches: 100,
+        functions: 100,
+        lines: 100,
+      },
+    },
+    include: ["test/**/*.spec.ts"],
+  },
+});