feat: add typeVersion validation to workflow validator (v2.6.1)

- Enhanced workflow validator to enforce typeVersion on versioned nodes
- Returns errors for missing typeVersion with suggested version to add
- Warns about outdated typeVersion values
- Prevents invalid typeVersion (zero, negative, or exceeding maximum)
- Added comprehensive test script for typeVersion validation
- Helps AI agents avoid common workflow creation mistakes

This ensures workflows always use compatible node versions before deployment.

🤖 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": "2.5.1",
+  "version": "2.6.1",
   "description": "Integration between n8n workflow automation and Model Context Protocol (MCP)",
   "main": "dist/index.js",
   "scripts": {
@@ -32,6 +32,7 @@
     "test:ai-workflow-validation": "node dist/scripts/test-ai-workflow-validation.js",
     "test:mcp-tools": "node dist/scripts/test-mcp-tools.js",
     "test:n8n-manager": "node dist/scripts/test-n8n-manager-integration.js",
+    "test:typeversion-validation": "node dist/scripts/test-typeversion-validation.js",
     "db:rebuild": "node dist/scripts/rebuild-database.js",
     "db:init": "node -e \"new (require('./dist/services/sqlite-storage-service').SQLiteStorageService)(); console.log('Database initialized')\"",
     "docs:rebuild": "ts-node src/scripts/rebuild-database.ts"