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/src/router.tsx

@@ -22,7 +22,6 @@ import {
   CommandsManagerPage,
   MemoryPage,
   SettingsPage,
-  HelpPage,
   NotFoundPage,
   LiteTasksPage,
   // LiteTaskDetailPage removed - now using TaskDrawer instead
@@ -157,10 +156,6 @@ const routes: RouteObject[] = [
         path: 'api-settings',
         element: <ApiSettingsPage />,
       },
-      {
-        path: 'help',
-        element: <HelpPage />,
-      },
       {
         path: 'hooks',
         element: <HookManagerPage />,
@@ -228,7 +223,6 @@ export const ROUTES = {
   SETTINGS_RULES: '/settings/rules',
   CODEXLENS_MANAGER: '/settings/codexlens',
   API_SETTINGS: '/api-settings',
-  HELP: '/help',
   EXPLORER: '/explorer',
   GRAPH: '/graph',
   TEAMS: '/teams',