chore: update n8n to ^1.104.1 and bump version to 2.8.1

- Updated n8n to ^1.104.1
- Updated n8n-core to ^1.103.1
- Updated n8n-workflow to ^1.101.0
- Updated @n8n/n8n-nodes-langchain to ^1.103.1
- Rebuilt node database with 532 nodes
- Sanitized 499 workflow templates
- All 1,182 tests passing (933 unit, 249 integration)
- All validation tests passing
- Built and prepared for npm publish

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

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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "n8n-mcp",
-  "version": "2.8.0",
+  "version": "2.8.1",
   "description": "Integration between n8n workflow automation and Model Context Protocol (MCP)",
   "main": "dist/index.js",
   "bin": {
@@ -115,13 +115,13 @@
   },
   "dependencies": {
     "@modelcontextprotocol/sdk": "^1.13.2",
-    "@n8n/n8n-nodes-langchain": "^1.102.1",
+    "@n8n/n8n-nodes-langchain": "^1.103.1",
     "axios": "^1.10.0",
     "dotenv": "^16.5.0",
     "express": "^5.1.0",
-    "n8n": "^1.103.2",
-    "n8n-core": "^1.102.1",
-    "n8n-workflow": "^1.100.0",
+    "n8n": "^1.104.1",
+    "n8n-core": "^1.103.1",
+    "n8n-workflow": "^1.101.0",
     "sql.js": "^1.13.0",
     "uuid": "^10.0.0"
   },