Monorepo skeleton, Prisma schema, core domain and services with tests

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

packages/core/src/flows/index.ts

@@ -0,0 +1,3 @@
+export * from './types.ts';
+export * from './definitions.ts';
+export * from './machine.ts';