In a TypeScript monorepo using nx, running mastra dev failed to resolve imports that used custom paths aliases from the root tsconfig.json (for example @my-project/constants pointing at libs/constants/src/index.ts), even though the paths worked fine everywhere else in the project. Importing workspace packages also failed with TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts". A direct tsx ./src/main.ts run worked, but that blocked use of the Mastra Playground.