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]>

packages/agent/README.md

@@ -0,0 +1,3 @@
+# @umt/agent
+
+Pi Agent 接入:AgentRuntimePort 封装、能力注册中心桥接、agent_run 持久化与测试用 fake 模型 provider。只通过显式白名单能力操作业务,不开放 bash/文件系统/任意网络。