Feat: add POSIX-lite bootstrap foundation

Docker/docker-compose.local.dev.yaml

@@ -6,6 +6,7 @@ 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
@@ -13,6 +14,7 @@ x-backend-service: &backend-service
       condition: service_healthy
   volumes:
     - ../Backend:/app
+    - ../POSIX:/posix
     - moku_work_backend_go_pkg:/go/pkg/mod
     - moku_work_backend_go_build:/root/.cache/go-build