GHSA-56C3-VFP2-5QQJ n8n-mcp's IPv4-mapped IPv6 addresses bypass SSRF protection in validateUrlSync(), enabling full SSRF for SDK embedders

Impact In the SDK embedder path N8NDocumentationMCPServer constructor, getN8nApiClient, and validateInstanceContext, the synchronous URL validator in SSRFProtection.validateUrlSync had no IPv6 checks. IPv4-mapped IPv6 addresses such as http://::ffff:169.254.169.254 bypassed the cloud-metadata,...