refactor: decouple docs-site from ccw monorepo

- Remove docs-frontend.ts utility and docs proxy from server.ts
- Remove docs startup logic from serve.ts
- Delete HelpPage.tsx and /help route from frontend
- Remove help navigation entry from Sidebar.tsx
- Clean /docs proxy from vite.config.ts
- Remove docs-related scripts from package.json files
- Delete help.spec.ts E2E tests
- Remove docs-site directory (migrated to D:\ccw-doc)

The docs-site has been moved to D:\ccw-doc as a standalone Docusaurus
project with baseUrl='/' for static hosting deployment (GitHub Pages/Netlify).

ccw/frontend/vite.config.ts

@@ -13,7 +13,7 @@ const __dirname = path.dirname(__filename)
 const basePath = process.env.VITE_BASE_URL || '/react/'
 
 // Backend target for Vite proxy (used when directly opening the Vite dev server port).
-// In `ccw view`, this is set to the dashboard server port so /api, /ws, and /docs all route correctly.
+// In `ccw view`, this is set to the dashboard server port so /api and /ws route correctly.
 const backendHost = process.env.VITE_BACKEND_HOST || 'localhost'
 const backendPort = Number(process.env.VITE_BACKEND_PORT || '3456')
 const backendHttpTarget = `http://${backendHost}:${backendPort}`
@@ -44,14 +44,6 @@ export default defineConfig({
         target: backendWsTarget,
         ws: true,
       },
-      // Docs proxy
-      // Forwards /docs requests to the dashboard server, which proxies to the docs server.
-      '/docs': {
-        target: backendHttpTarget,
-        changeOrigin: true,
-        // Preserve /docs prefix to match the dashboard's /docs proxy and Docusaurus baseUrl.
-        // Example: /docs/overview -> http://localhost:{backendPort}/docs/overview
-      },
     },
   },
   build: {