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]>

.env.example

@@ -0,0 +1,9 @@
+# 复制为 .env 后按需修改(apps/server 与 packages/db 都会读取仓库根的 .env)
+PORT=4380
+DATABASE_URL=postgres://umt:umt@localhost:55433/umt
+# 凭证加密主密钥(32 字节以上随机串);与数据库备份分开保管
+SECRET_MASTER_KEY=dev-only-change-me-dev-only-change-me
+LOG_LEVEL=info
+NODE_ENV=development
+# 开发模式下可直接用此 Key 以 admin scope 访问 API;生产环境忽略
+DEV_ADMIN_KEY=umt-dev-admin-key