chore: scaffold monorepo and migrate uhd_web design system (W0-A)

- pnpm workspace: apps/{web,server}, packages/{contracts,db,domain,adapters,tasks,agent,testkit}
- server: Hono + zod-openapi, API Key auth with scopes, redacting pino logger, SSE event bus with replay, worker heartbeat
- db: Kysely + pg, file migrator, 0001_init (settings/api_key/audit_event/outbox_event)
- web: React Router 7 SPA console shell with 12 workspace placeholders, uhd_web tokens/ui/guard scripts
- docs: ADR-001 (Node over Deno), dev runbook, design system rules

Co-Authored-By: Claude Fable 5.1 <[email protected]>

apps/web/app/routes/console/sites.tsx

@@ -0,0 +1,6 @@
+import { WorkspacePlaceholder } from "~/components/console/workspace-placeholder";
+
+// 占位:标题与说明取自 components/console/nav.ts
+export default function SitesPage() {
+  return <WorkspacePlaceholder />;
+}