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/db/src/index.ts

@@ -0,0 +1,5 @@
+// 统一从本包取 Kysely 与 sql,避免各包各装一份 kysely
+export { type Kysely, sql, type Transaction } from "kysely";
+export { type CreateDbOptions, createDb } from "./client";
+export { createMigrator, MIGRATIONS_DIR, migrateToLatest, resetSchema } from "./migrator";
+export type * from "./types";