chore: update n8n to 2.11.4 (#634)

* chore: update n8n to 2.11.4 and bump version to 2.36.2

- Updated n8n from 2.10.3 to 2.11.4
- Updated n8n-core from 2.10.1 to 2.11.1
- Updated n8n-workflow from 2.10.1 to 2.11.1
- Updated @n8n/n8n-nodes-langchain from 2.10.1 to 2.11.2
- Updated @modelcontextprotocol/sdk from 1.20.1 to 1.27.1 (critical security fix)
- Rebuilt node database with 1,239 nodes (809 core + 430 community preserved)
- Updated README badge with new n8n version and node counts
- Updated CHANGELOG with dependency changes

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(ci): update MCP SDK version check from 1.20.1 to 1.27.1

The dependency-check workflow was hardcoded to expect MCP SDK 1.20.1,
causing CI failure after the intentional upgrade to 1.27.1.

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(tests): close existing connection before reconnecting in MCP protocol tests

MCP SDK 1.27+ enforces single-connection per Server instance, throwing
"Already connected to a transport" when connect() is called twice.
Updated test helper to close existing connections before reconnecting.

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "n8n-mcp",
-  "version": "2.36.1",
+  "version": "2.36.2",
   "description": "Integration between n8n workflow automation and Model Context Protocol (MCP)",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
@@ -152,17 +152,17 @@
     "vitest": "^3.2.4"
   },
   "dependencies": {
-    "@modelcontextprotocol/sdk": "1.20.1",
-    "@n8n/n8n-nodes-langchain": "^2.10.1",
+    "@modelcontextprotocol/sdk": "^1.27.1",
+    "@n8n/n8n-nodes-langchain": "^2.11.2",
     "@supabase/supabase-js": "^2.57.4",
     "dotenv": "^16.5.0",
     "express": "^5.1.0",
     "express-rate-limit": "^7.1.5",
     "form-data": "^4.0.5",
     "lru-cache": "^11.2.1",
-    "n8n": "^2.10.3",
-    "n8n-core": "^2.10.1",
-    "n8n-workflow": "^2.10.1",
+    "n8n": "^2.11.4",
+    "n8n-core": "^2.11.1",
+    "n8n-workflow": "^2.11.1",
     "openai": "^4.77.0",
     "sql.js": "^1.13.0",
     "tslib": "^2.6.2",