feat(tests): implement Phase 2 integration testing - workflow creation tests

Implements comprehensive workflow creation tests against real n8n instance
with 15 test scenarios covering P0 bugs, base nodes, advanced features,
error scenarios, and edge cases.

Key Changes:
- Added 15 workflow creation test scenarios in create-workflow.test.ts
- Fixed critical MSW interference with real API calls
- Fixed environment loading priority (.env before test defaults)
- Implemented multi-level cleanup with webhook workflow preservation
- Migrated from webhook IDs to webhook URLs configuration
- Added TypeScript type safety fixes (26 errors resolved)
- Updated test names to reflect actual n8n API behavior

Bug Fixes:
- Removed MSW from integration test setup (was blocking real API calls)
- Fixed .env loading order to preserve real credentials over test defaults
- Added type guards for undefined workflow IDs
- Fixed position arrays to use proper tuple types [number, number]
- Added literal types for executionOrder and settings values

Test Coverage:
- P0: Critical bug verification (FULL vs SHORT node type format)
- P1: Base n8n nodes (webhook, HTTP, langchain, multi-node)
- P2: Advanced features (connections, settings, expressions, error handling)
- Error scenarios (documents actual n8n API validation behavior)
- Edge cases (minimal workflows, empty connections, no settings)

Technical Improvements:
- Cleanup strategy preserves pre-activated webhook workflows
- Single webhook URL accepts all HTTP methods (GET, POST, PUT, DELETE)
- Environment-aware credential loading with validation
- Comprehensive test context for resource tracking

All 15 tests passing ✅
TypeScript: 0 errors ✅

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

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

scripts/export-webhook-workflows.ts

@@ -0,0 +1,41 @@
+#!/usr/bin/env tsx
+
+/**
+ * Export Webhook Workflow JSONs
+ *
+ * Generates the 4 webhook workflow JSON files needed for integration testing.
+ * These workflows must be imported into n8n and activated manually.
+ */
+
+import { writeFileSync, mkdirSync } from 'fs';
+import { join } from 'path';
+import { exportAllWebhookWorkflows } from '../tests/integration/n8n-api/utils/webhook-workflows';
+
+const OUTPUT_DIR = join(process.cwd(), 'workflows-for-import');
+
+// Create output directory
+mkdirSync(OUTPUT_DIR, { recursive: true });
+
+// Generate all workflow JSONs
+const workflows = exportAllWebhookWorkflows();
+
+// Write each workflow to a separate file
+Object.entries(workflows).forEach(([method, workflow]) => {
+  const filename = `webhook-${method.toLowerCase()}.json`;
+  const filepath = join(OUTPUT_DIR, filename);
+
+  writeFileSync(filepath, JSON.stringify(workflow, null, 2), 'utf-8');
+
+  console.log(`✓ Generated: ${filename}`);
+});
+
+console.log(`\n✓ All workflow JSONs written to: ${OUTPUT_DIR}`);
+console.log('\nNext steps:');
+console.log('1. Import each JSON file into your n8n instance');
+console.log('2. Activate each workflow in the n8n UI');
+console.log('3. Copy the webhook URLs from each workflow (open workflow → Webhook node → copy URL)');
+console.log('4. Add them to your .env file:');
+console.log('   N8N_TEST_WEBHOOK_GET_URL=https://your-n8n.com/webhook/mcp-test-get');
+console.log('   N8N_TEST_WEBHOOK_POST_URL=https://your-n8n.com/webhook/mcp-test-post');
+console.log('   N8N_TEST_WEBHOOK_PUT_URL=https://your-n8n.com/webhook/mcp-test-put');
+console.log('   N8N_TEST_WEBHOOK_DELETE_URL=https://your-n8n.com/webhook/mcp-test-delete');