docs(spikes): Deno 2.9.7 + TS 7 compatibility spike and ADR-004

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

spikes/deno/web/app/api/health.ts

@@ -0,0 +1,13 @@
+import { useQuery } from "@tanstack/react-query";
+import type { HealthStatus } from "@umt/contracts";
+import { apiData, TTL_SECOND } from "~/lib/api";
+
+/** 服务健康状态,15 秒轮询 */
+export function useHealth() {
+  return useQuery({
+    queryKey: ["health"],
+    queryFn: ({ signal }) => apiData<HealthStatus>("/api/v1/health", { signal }),
+    refetchInterval: 15 * TTL_SECOND,
+    retry: false,
+  });
+}