fix: recognize dynamic AI Tool nodes in validator (Issue #522) (#526)

When n8n connects any node to an AI Agent's tool slot, it creates a
dynamic Tool variant at runtime (e.g., googleDrive → googleDriveTool).
These don't exist in npm packages, causing false "unknown node type"
errors.

Added validation-time inference: when a *Tool node type is not found,
check if the base node exists. If yes, treat as valid with warning.

Changes:
- workflow-validator.ts: Add INFERRED_TOOL_VARIANT logic
- node-similarity-service.ts: Add 98% confidence for valid Tool variants
- Added 7 unit tests for inferred tool variant functionality

Fixes #522

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

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

Co-authored-by: Romuald Członkowski <romualdczlonkowski@MacBook-Pro-Romuald.local>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "n8n-mcp",
-  "version": "2.31.8",
+  "version": "2.31.9",
   "description": "Integration between n8n workflow automation and Model Context Protocol (MCP)",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",