mosquitto: run mosquitto_ctrl inside the broker's container

The module's code moved out of its container and took mosquitto_ctrl from a host package. A
machine whose package index is stale cannot install it (hq issue 205), so the tools failed. The
broker's own image carries the tool at the broker's version: the tools exec into the running
broker, and the bootstrap seeds from a throwaway container of the same image.

modules/mosquitto/test/ctrl.test.ts

@@ -0,0 +1,19 @@
+// Run after `npm run build`.
+// mosquitto_ctrl runs inside the broker's own container when the manifest names it, so a machine
+// needs no mosquitto package (whose index may be too stale to install from) and the tool always
+// matches the broker's version.
+import assert from "node:assert/strict";
+import { test } from "node:test";
+import { MosquittoClient } from "../dist/client.js"; // compiled: client.ts uses parameter properties, which type stripping cannot run
+
+const env = { MESH_PROVISION_MQTT: "127.0.0.1:21883", MESH_MQTT_PASSWORD: "pw" };
+
+test("named, the broker's container runs mosquitto_ctrl", () => {
+  const c = MosquittoClient.fromEnv({ ...env, MESH_MQTT_CTRL_CONTAINER: "mosquitto" });
+  assert.deepEqual(c.ctrl(["dynsec", "listClients"]), ["docker", ["exec", "mosquitto", "mosquitto_ctrl", "dynsec", "listClients"]]);
+});
+
+test("unnamed, this machine's mosquitto_ctrl runs", () => {
+  const c = MosquittoClient.fromEnv(env);
+  assert.deepEqual(c.ctrl(["dynsec", "listClients"]), ["mosquitto_ctrl", ["dynsec", "listClients"]]);
+});