dsh-apple-mode: Connect Xcode AI stack to DSH sessions using agent presets

# Introduction If you are writing Swift on macOS using DeepSeek Harness (dsh), you have likely encountered this awkward situation: the model can generate SwiftUI code, but cannot access the Xcode project itself—creating targets, modifying build settings, switching schemes and run targets, reading diagnostic information, and editing the String Catalog—all of these tasks require you to manually switch back to Xcode. The philosophy behind dsh is that everything is a plugin, and since Xcode 26, Apple has officially provided `mcpbridge`, allowing external tools to directly manipulate open projects. This article introduces jihongboo/dsh-apple-mode, which brings this capability to DSH.