Upgrade to .NET 10 LTS and System.Management.Automation 7.6.1

[MariusStorhaug]

Context

PR #45 initially targeted .NET 10.0\ and \System.Management.Automation 7.6.1\ as part of the Sodium hardening effort. However, these upgrades were reverted to .NET 8.0\ and \7.4.7\ due to compatibility issues with the native interop layer during the DllImport → LibraryImport source-generator migration.

Request

Upgrade the PSModule.Sodium project to leverage the latest stable versions:

• .NET 10.0 (latest LTS)
• System.Management.Automation 7.6.1 (latest stable)

These are now mature and should support LibraryImport source generators without the issues encountered in PR #45.

Technical Context

The previous attempt (PR #45, commit 9326f7c) revealed compatibility concerns with:

• LibraryImport attribute and source-generator marshalling interoperability
• Native DLL loading paths under .NET 10.0
• Buffer marshalling and safety guarantees in the newer runtime

Acceptance Criteria

• Project file targets .NET 10.0\
• System.Management.Automation updated to \7.6.1\
• All native interop (LibraryImport) methods compile and run correctly
• Unit tests pass on Windows, Linux, and macOS
• Performance benchmarks match or exceed the .NET 8.0 baseline
• No regressions in error handling or validation

Related

• PR 🩹 [Patch]: Secret crypto operations now fail fast on invalid input with lower per-call overhead #45: Harden Sodium native interop and reduce per-call cryptographic overhead
• Issue Perf: Migrate P/Invoke signatures from DllImport to LibraryImport #48: Migrate DllImport to LibraryImport source generator

[MariusStorhaug]

Marking this issue as blocked pending GitHub-hosted runner image updates to PowerShell 7.6 LTS. Current runners are on PowerShell 7.4.x and fail to import the net10.0-targeted module assembly in CI. Work will resume once runner PowerShell baseline is updated.