Support shadcn UI generation in workspace applets

[tonyfresher]

Workspace applets can now generate and bundle shadcn controls with the same semantic tokens, radius scale, icons, and scoped Tailwind behavior as moi. New workspaces also receive the official shadcn skill, while existing .moi scaffolds remain untouched.

moi workspace init
├─ install the official shadcn skill
├─ scaffold components.json, TypeScript aliases, and local cx/cn
└─ generated control → scoped applet CSS → host theme tokens

What changed

• Scaffold the shadcn project config, applet TypeScript config, local class helper, and required dependencies
• Bundle shadcn state variants, animations, semantic borders, and outlines inside scoped applet CSS
• Install the official shadcn skill for Claude Code, Codex, and OpenClaw workspaces
• Refresh the official skill through CLI and workspace API updates with explicit failure reporting
• Teach the moi workspace skill to generate kind-local controls and keep portals inside the applet root
• Bump the bundled workspace skill version from 0.8.0 to 0.9.0

Review focus

• Check external skill installation environment, timeout, and offline fallback behavior
• Check generated import paths and the idempotent scaffold guard for existing .moi folders
• Check CSS ordering and scoping for shadcn data variants, animations, borders, and theme ownership

Verification

• Focused applet, scaffold, installer, workspace-init, API, CLI, and skill tests — 75 passed
• bun test — 608 passed
• bun run format:check, bun run lint, and bun run typecheck:client
• One commit and a clean diff against design-guidelines

Stacked on #56 and intended to merge after it.