fix: preserve immutable monitor migration sources

scripts/src/monitor-central-persistence.test.ts

@@ -32,6 +32,14 @@ test("HTTP terminal ingest is unbound-safe, ignores caller hash, and maps confli
   assert.equal((await fetch(new Request("http://local/health"))).status, 200);
 });
 
+test("health returns 503 when the central store is not ready", async () => {
+  const store = createInMemoryMonitorCentralStore();
+  const target = createMonitorCentralService({ store: { ...store, async ping() { throw new Error("postgres unavailable"); } }, pageSize: 50 });
+  const response = await target.fetch(new Request("http://local/health"));
+  assert.equal(response.status, 503);
+  assert.equal((await response.json() as { ok: boolean }).ok, false);
+});
+
 test("full terminal envelope controls hash and concurrent same identity converges", async () => {
   const target = service();
   const base = { ...input("run-envelope"), payloadHash: "sha256:caller-controlled" };