diff --git a/test/integration/assigned-vault.test.ts b/test/integration/assigned-vault.test.ts
index 1059194..b3eaf9a 100644
--- a/test/integration/assigned-vault.test.ts
+++ b/test/integration/assigned-vault.test.ts
@@ -433,3 +433,33 @@ test("the operator recovers a root secret with a key the mesh never held, from t
   assert.ok(listed.some((k) => k.module === "mesh-vault" && k.name === "broker"), JSON.stringify(served));
   assert.ok(!JSON.stringify(served).includes(onDisk), "secret_export returned a plaintext value");
 });
+
+test("a seeded file is created once, and what a program grows in it survives the next push", {
+  skip, timeout: 600_000,
+}, async () => {
+  // novox/hq ADR 0087, issue 035. A file that says create-once is written when absent and left
+  // alone when present — content, mode and owner — so an access list a program persists into is
+  // not restored to its seed behind the program's back on every reconcile.
+  const manifest = JSON.stringify({
+    module: "seed-test", version: "1",
+    resources: [
+      { id: "dir", type: "directory", path: "/var/lib/seed-test", mode: "0755" },
+      { id: "acl", type: "file", path: "/var/lib/seed-test/acl.conf", mode: "0600", "create-once": true,
+        content: "user default on\n" },
+    ],
+  });
+  await must(`printf %s ${quote(manifest)} > /tmp/seed-test.json && docker cp /tmp/seed-test.json mesh-controller:/seed-test.json`);
+  await mesh("module add /seed-test.json");
+  await mesh(`assign ${MACHINE} seed-test`);
+  await mesh(`push ${MACHINE}`);
+  await settled();
+  assert.equal(await must(`cat /var/lib/seed-test/acl.conf`), "user default on\n");
+
+  // The program grows it.
+  await must(`printf 'user app-one on >secret\n' >> /var/lib/seed-test/acl.conf`);
+  // A second push: the mesh reconciles everything it declared, and leaves the seed alone.
+  await mesh(`push ${MACHINE}`);
+  await settled();
+  assert.equal(await must(`cat /var/lib/seed-test/acl.conf`), "user default on\nuser app-one on >secret\n",
+    "the seed was restored and what the program wrote into it was wiped");
+});
diff --git a/test/integration/one-node-mesh.test.ts b/test/integration/one-node-mesh.test.ts
index 83c1855..7fcfcaa 100644
--- a/test/integration/one-node-mesh.test.ts
+++ b/test/integration/one-node-mesh.test.ts
@@ -40,6 +40,7 @@ import { test, before, after } from "node:test";
 import assert from "node:assert/strict";
 import { existsSync, readFileSync, writeFileSync, appendFileSync } from "node:fs";
 import { execFileSync } from "node:child_process";
+import net from "node:net";
 import { resolve } from "node:path";
 import { loadScenario } from "../../src/declaration/parse.ts";
 import { raise } from "../../src/lifecycle/raise.ts";
@@ -247,6 +248,31 @@ async function mesh(command: string, timeoutMs?: number): Promise<string> {
   }
 }
 
+/** The machine's address on the lab's uplink bridge — the one the workstation can dial. */
+async function uplinkAddressOf(machine: string): Promise<string> {
+  const name = await instanceNameOf(instanceId, machine);
+  const listed = (await incus(["list", name, "--format", "csv", "-c", "4"], 30_000)).stdout;
+  const addresses = listed.split(/[,\s]+/).map((a: string) => a.trim()).filter((a: string) => /^10\./.test(a));
+  assert.ok(addresses.length > 0, `no uplink address for ${machine} in:\n${listed}`);
+  return addresses[0] as string;
+}
+
+/** Try to open a TCP connection every two seconds to each port, and remember whether any attempt ever succeeded. */
+function probeFromOutside(address: string, ports: number[]): { stop(): void; seen(): Map<number, boolean> } {
+  const seen = new Map<number, boolean>(ports.map((p) => [p, false]));
+  const attempt = () => {
+    for (const port of ports) {
+      const socket = net.connect({ host: address, port, timeout: 1000 });
+      socket.once("connect", () => { seen.set(port, true); socket.destroy(); });
+      socket.once("timeout", () => socket.destroy());
+      socket.once("error", () => socket.destroy());
+    }
+  };
+  attempt();
+  const timer = setInterval(attempt, 2000);
+  return { stop: () => clearInterval(timer), seen: () => seen };
+}
+
 /** Until the anchor reports the last declaration genesis pushed as applied and current. */
 async function settledAfterGenesis(withinMs = 300_000): Promise<void> {
   const deadline = Date.now() + withinMs;
@@ -508,6 +534,11 @@ before(async () => {
   // nothing held: no image is pre-resolved, because none is here to resolve to.
   await step("R1", GENESIS, null, async () => {
     try {
+      // Probed from the workstation for the whole install (novox/hq ADR 0088, issue 054): the
+      // store's client port must never answer from outside the machine, while the bus's must
+      // come to — which is also what proves the probe reaches the machine at all.
+      const probe = probeFromOutside(await uplinkAddressOf(CONTROL), [5432, 5671]);
+      try {
       raised = await genesis({
         instanceId,
         node: CONTROL,
@@ -538,6 +569,15 @@ before(async () => {
         ...(binary ? { hostBinary: binary } : {}),
         log: (m) => console.log(m),
       });
+      } finally {
+        probe.stop();
+      }
+      const seen = probe.seen();
+      assert.equal(seen.get(5432), false,
+        "the store's port answered from outside the machine during the install — the base filter did not hold (issue 054)");
+      assert.equal(seen.get(5671), true,
+        "the bus never answered from outside during the install, so the probe proves nothing — is the uplink address right?");
+      raised.report.push(`  filtered          5432 never answered from outside during the install; 5671 did`);
     } catch (err) {
       throw new Error(`the installer never ran: ${(err as Error).message}`);
     }