One SDK per runtime: a bundle's SDK import resolves to the runtime's copy (hq issue 209)

A bundle carries its dependencies, the SDK among them; imported in-process that copy was a
second SDK with its own tool registry, so a bundle registered its tools into a list the
runtime never read and served nothing, silently. A resolve hook (module.registerHooks, in
thread; module.register is deprecated from Node 26) now sends every import of
@novox/mesh-sdk, from whichever bundle, to the runtime's own copy: one registry, one broker.
The test loads a bundle from a directory holding its own SDK copy and sees its tool served.

node-tools/test/node-runtime.test.ts

@@ -11,6 +11,9 @@
 import assert from "node:assert/strict";
 import { test } from "node:test";
 import { fileURLToPath } from "node:url";
+import { cpSync, mkdirSync, mkdtempSync, realpathSync, rmSync, writeFileSync } from "node:fs";
+import { join } from "node:path";
+import { tmpdir } from "node:os";
 import { connect, StringCodec } from "nats";
 
 import { resetTools } from "@novox/mesh-sdk/tools";
@@ -192,3 +195,49 @@ test("the node's runtime serves five modules' bundles on one credential — two
     resetTools();
   }
 });
+
+test("a bundle carrying its own copy of the SDK registers into the runtime's registry, and its tools are served (issue 209)", async (t) => {
+  if (!url) return t.skip("MESH_TEST_NATS unset");
+  resetTools();
+  let dir = "";
+  let stop = () => {};
+  const closing: Array<() => Promise<void>> = [];
+  const said: string[] = [];
+  const log = console.log;
+  try {
+    // A bundle as the toolchain packs one: its compiled entrypoint, a package.json saying ES modules,
+    // and its dependencies copied in — the SDK among them, a second copy beside the runtime's own,
+    // and a dependency of the bundle's own that the runtime does not carry.
+    dir = mkdtempSync(join(tmpdir(), "mesh-bundle-"));
+    const sdk = realpathSync(fileURLToPath(new URL("../node_modules/@novox/mesh-sdk/", import.meta.url)));
+    cpSync(sdk, join(dir, "node_modules", "@novox", "mesh-sdk"), { recursive: true });
+    mkdirSync(join(dir, "node_modules", "zeta-flavour"), { recursive: true });
+    writeFileSync(join(dir, "node_modules", "zeta-flavour", "package.json"), '{"name":"zeta-flavour","type":"module","main":"index.js"}\n');
+    writeFileSync(join(dir, "node_modules", "zeta-flavour", "index.js"), 'export const flavour = "the bundle\'s own";\n');
+    writeFileSync(join(dir, "package.json"), '{"type":"module","private":true}\n');
+    writeFileSync(join(dir, "index.js"),
+      'import { registerModuleTools } from "@novox/mesh-sdk/tools";\n' +
+      'import { flavour } from "zeta-flavour";\n' +
+      'registerModuleTools("zeta", () => [{ name: "probe", description: "answers", input: {}, run: async () => ({ zeta: true, flavour }) }]);\n');
+    const mesh = await aMesh();
+    closing.push(() => mesh.close());
+    await mesh.issue(membershipOf("zeta", "anchor"));
+    const credential = { url, node: "anchor", module: "node-tools" };
+    const nodeTools = await connectNats(credential);
+    closing.push(() => nodeTools.close());
+    const asker = await connectNats({ url, module: "console", node: "workstation" });
+    closing.push(() => asker.close());
+    console.log = (...a: unknown[]) => said.push(a.join(" "));
+    stop = await runTools({ broker: nodeTools, credential, serves: [{ module: "zeta", entrypoints: [join(dir, "index.js")] }] });
+    console.log = log;
+    assert.ok(said.some((s) => /serving 1 tool\(s\) for 1 module\(s\): zeta\.probe/.test(s)), said.join("\n"));
+    // The SDK is the runtime's (the registration arrived); the bundle's other dependency is its own.
+    assert.deepEqual((await callTool(asker, "zeta.probe@anchor", {})).result, { zeta: true, flavour: "the bundle's own" });
+  } finally {
+    console.log = log;
+    stop();
+    for (const close of closing.reverse()) await close();
+    if (dir) rmSync(dir, { recursive: true, force: true });
+    resetTools();
+  }
+});