chore(n8n): publish under the scoped @mem0/n8n-nodes-mem0 name

The unscoped `n8n-nodes-mem0` name is already taken on npm by an
unrelated publisher, so the CD workflow could never publish it. Move to
the `@mem0` scope, matching `@mem0/pi-agent-plugin` and
`@mem0/openclaw-mem0`, and add `publishConfig.access: public` since
scoped packages default to restricted.

n8n accepts scoped community packages: it strips the scope before
enforcing the `n8n-nodes-` prefix, the same shape as n8n's own
`@n8n/n8n-nodes-langchain`. Verified end to end on n8n 2.22.6 by
installing the packed tarball into the community-packages directory and
executing a workflow against node type `@mem0/n8n-nodes-mem0.mem0`.

The directory, workflow filenames, and the `n8n-nodes-mem0-v*` tag
prefix are unchanged. pnpm-lock.yaml needs no update: the pnpm v9 root
importer is anonymous and never recorded the package name.

integrations/n8n-nodes-mem0/package.json

@@ -1,5 +1,5 @@
 {
-  "name": "n8n-nodes-mem0",
+  "name": "@mem0/n8n-nodes-mem0",
   "version": "0.1.0",
   "description": "n8n community node for Mem0 — the memory layer for AI agents. Add, search, get, update, and delete long-term memories.",
   "keywords": [
@@ -25,6 +25,9 @@
     "node": ">=20.15"
   },
   "main": "index.js",
+  "publishConfig": {
+    "access": "public"
+  },
   "scripts": {
     "build": "npx rimraf dist && tsc && gulp build:icons",
     "dev": "tsc --watch",