fix: resolve test failures and improve node categorization

- Fix method name mismatches in template repository tests
- Enhance node categorization logic for AI/ML nodes
- Correct test expectations for metadata search
- Add missing schema properties in MCP tools
- Improve detection of agent and OpenAI nodes

All 21 failing tests now passing

🤖 Generated with Claude Code

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

src/mcp/tools.ts

@@ -519,6 +519,7 @@ export const n8nDocumentationToolsFinal: ToolDefinition[] = [
           minimum: 0,
         },
       },
+      additionalProperties: false,
     },
   },
   {