fix: add rootDir to tsconfig.json for TypeScript 6 compatibility

Agent-Logs-Url: https://github.com/mikro-orm/koa-ts-example-app/sessions/9018dce7-b82b-4ace-ac37-af251cb3cdac

Co-authored-by: B4nan <615580+B4nan@users.noreply.github.com>

Author: Copilot

tsconfig.json

@@ -4,6 +4,7 @@
     "target": "ESNext",
     "moduleResolution": "NodeNext",
     "declaration": true,
+    "rootDir": "./app",
     "outDir": "./dist",
     "esModuleInterop": true,
     "emitDecoratorMetadata": true,