subagenttasks

Adopt apps/subagentswift-mcp's Package.swift-based build (no .xcodeproj) as the documented reference for why Xcode-specific tooling isn't yet needed

The conduit's Swift package builds via SPM/Package.swift, proven both on macOS and inside a Lima Linux VM. Adopt this as the explicit reason cwc-xcode-engineering has no current target — SPM-only builds don't need Xcode project tooling.