Feat: add POSIX-lite bootstrap foundation

Docker/docker-compose.local.prod.yaml

@@ -5,11 +5,14 @@ x-backend-service: &backend-service
   environment:
     DATABASE_URL: postgres://moku:moku_dev_password@postgres:5432/moku?sslmode=disable
     VALKEY_URL: redis://valkey:6379/0
+    POSIX_ROOT: /posix
   depends_on:
     postgres:
       condition: service_healthy
     valkey:
       condition: service_healthy
+  volumes:
+    - ../POSIX:/posix
 
 services:
   postgres: