chore: update n8n dependencies to v1.112.3

- Updated n8n from 1.111.0 to 1.112.3
- Updated n8n-core from 1.110.0 to 1.111.0
- Updated n8n-workflow from 1.108.0 to 1.109.0
- Updated @n8n/n8n-nodes-langchain from 1.110.0 to 1.111.1
- Rebuilt node database with 536 nodes (438 from n8n-nodes-base, 98 from langchain)
- Bumped version to 2.12.2
- Updated README.md badges to reflect new n8n version

🤖 Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "n8n-mcp",
-  "version": "2.12.1",
+  "version": "2.12.2",
   "description": "Integration between n8n workflow automation and Model Context Protocol (MCP)",
   "main": "dist/index.js",
   "bin": {
@@ -128,13 +128,13 @@
   },
   "dependencies": {
     "@modelcontextprotocol/sdk": "^1.13.2",
-    "@n8n/n8n-nodes-langchain": "^1.110.0",
+    "@n8n/n8n-nodes-langchain": "^1.111.1",
     "dotenv": "^16.5.0",
     "express": "^5.1.0",
     "lru-cache": "^11.2.1",
-    "n8n": "^1.111.0",
-    "n8n-core": "^1.110.0",
-    "n8n-workflow": "^1.108.0",
+    "n8n": "^1.112.3",
+    "n8n-core": "^1.111.0",
+    "n8n-workflow": "^1.109.0",
     "openai": "^4.77.0",
     "sql.js": "^1.13.0",
     "uuid": "^10.0.0",