fix: resolve tool count discrepancy in Docker environments (#6)

- Implement dynamic n8n API configuration checking
- Remove static config export in favor of lazy getter function
- Fix management tools not being registered when env vars set after startup
- Optimize logger performance with cached environment variables
- Clean up debug logging and remove console.error usage
- Bump version to 2.7.1

This ensures all 38 tools (22 documentation + 16 management) are properly
registered regardless of when environment variables become available.

🤖 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": "2.7.0",
+  "version": "2.7.1",
   "description": "Integration between n8n workflow automation and Model Context Protocol (MCP)",
   "main": "dist/index.js",
   "scripts": {