Switch oss.cs CLI arg parsing to ConsoleAppFramework

[Copilot]

System.CommandLine required significant boilerplate for what is just three optional string options: explicit Option<T> objects, RootCommand wiring, and SetHandler with repeated option references.

Changes

• Drop System.CommandLine@2.0.7 in favor of ConsoleAppFramework@*
• Replace Option<> / RootCommand / SetHandler setup with a single ConsoleApp.RunAsync lambda — parameters auto-bind to --project, --repo, --package

// Before: ~10 lines of plumbing + SetHandler(..., projectOption, repoOption, packageOption)
// After:
await ConsoleApp.RunAsync(args, async (
    /// <summary>Project name</summary>
    string? project = null,
    /// <summary>Repo name (defaults to project name)</summary>
    string? repo = null,
    /// <summary>Package ID (defaults to Devlooped.{project})</summary>
    string? package = null) =>
{
    // handler body unchanged
});