feat: Add support for virt package

- Add sal-virt package to the workspace members
- Update MONOREPO_CONVERSION_PLAN.md to reflect the
  completion of sal-process and sal-virt packages
- Update src/lib.rs to include sal-virt
- Update src/postgresclient to use sal-virt instead of local
  virt module
- Update tests to use sal-virt

virt/src/lib.rs

@@ -0,0 +1,33 @@
+//! # SAL Virt Package
+//! 
+//! The `sal-virt` package provides comprehensive virtualization and containerization tools
+//! for building, managing, and deploying containers and filesystem layers.
+//! 
+//! ## Features
+//! 
+//! - **Buildah**: OCI/Docker image building with builder pattern API
+//! - **Nerdctl**: Container lifecycle management with containerd
+//! - **RFS**: Remote filesystem mounting and layer management
+//! - **Cross-Platform**: Works across Windows, macOS, and Linux
+//! - **Rhai Integration**: Full support for Rhai scripting language
+//! - **Error Handling**: Comprehensive error types and handling
+//! 
+//! ## Modules
+//! 
+//! - [`buildah`]: Container image building with Buildah
+//! - [`nerdctl`]: Container management with Nerdctl
+//! - [`rfs`]: Remote filesystem operations
+//! 
+//! This package depends on `sal-process` for command execution and `sal-os` for 
+//! filesystem operations.
+
+pub mod buildah;
+pub mod nerdctl;
+pub mod rfs;
+
+pub mod rhai;
+
+// Re-export main types and functions for convenience
+pub use buildah::{Builder, BuildahError, ContentOperations};
+pub use nerdctl::{Container, NerdctlError, HealthCheck, ContainerStatus};
+pub use rfs::{RfsBuilder, PackBuilder, RfsError, Mount, MountType, StoreSpec};