chore: update n8n to v1.105.2 and dependencies

- Updated n8n from 1.104.1 to 1.105.2
- Updated n8n-core from 1.103.1 to 1.104.1
- Updated n8n-workflow from 1.101.0 to 1.102.1
- Updated @n8n/n8n-nodes-langchain from 1.103.1 to 1.104.1
- Rebuilt node database with 534 nodes
- All 1,620 tests passing
- Updated CHANGELOG.md

🤖 Generated with [Claude Code](https://claude.ai/code)

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

package.json

@@ -128,12 +128,12 @@
   },
   "dependencies": {
     "@modelcontextprotocol/sdk": "^1.13.2",
-    "@n8n/n8n-nodes-langchain": "^1.103.1",
+    "@n8n/n8n-nodes-langchain": "^1.104.1",
     "dotenv": "^16.5.0",
     "express": "^5.1.0",
-    "n8n": "^1.104.1",
-    "n8n-core": "^1.103.1",
-    "n8n-workflow": "^1.101.0",
+    "n8n": "^1.105.2",
+    "n8n-core": "^1.104.1",
+    "n8n-workflow": "^1.102.1",
     "sql.js": "^1.13.0",
     "uuid": "^10.0.0"
   },