feat: add n8n_create_data_table MCP tool and projectId for create workflow (#640)

Add new MCP tool to create n8n data tables via the REST API:
- n8n_create_data_table tool definition with name + columns schema
- handleCreateDataTable handler with Zod validation and N8nApiError handling
- N8nApiClient.createDataTable() calling POST /data-tables
- DataTable, DataTableColumn, DataTableColumnResponse types per OpenAPI spec
- Column types: string | number | boolean | date | json
- Input validation: .min(1) on table name and column names
- Tool documentation with examples, use cases, and pitfalls

Also adds projectId parameter to n8n_create_workflow for enterprise
project support, and fixes stale management tool count in health check.

Based on work by @djakielski in PR #646.
Co-Authored-By: Dominik Jakielski <dominik.jakielski@urlaubsguru.de>

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

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/unit/mcp/parameter-validation.test.ts

@@ -542,6 +542,9 @@ describe('Parameter Validation', () => {
       await expect(server.testExecuteTool('n8n_test_workflow', {}))
         .rejects.toThrow('Missing required parameters for n8n_test_workflow: workflowId');
 
+      await expect(server.testExecuteTool('n8n_create_data_table', {}))
+        .rejects.toThrow('Missing required parameters for n8n_create_data_table: name');
+
       for (const tool of n8nToolsWithRequiredParams) {
         await expect(server.testExecuteTool(tool.name, tool.args))
           .rejects.toThrow(tool.expected);