fix: correct misleading Code node documentation based on real-world testing

Critical fixes based on Claude Desktop feedback:

1. Fixed crypto documentation: require('crypto') IS available despite editor warnings
   - Added clear examples of crypto usage
   - Updated validation to guide correct require() usage

2. Clarified $helpers vs standalone functions
   - $getWorkflowStaticData() is standalone, NOT $helpers.getWorkflowStaticData()
   - Added validation to catch incorrect usage (prevents '$helpers is not defined' errors)
   - Enhanced examples showing proper $helpers availability checks

3. Fixed JMESPath numeric literal documentation
   - n8n requires backticks around numbers in filters: [?age >= `18`]
   - Added multiple examples and validation to detect missing backticks
   - Prevents 'JMESPath syntax error' that Claude Desktop encountered

4. Fixed webhook data access gotcha
   - Webhook payload is at items[0].json.body, NOT items[0].json
   - Added dedicated 'Webhook Data Access' section with clear examples
   - Created process_webhook_data task template
   - Added validation to detect incorrect webhook data access patterns

All fixes based on production workflows TaNqYoZNNeHC4Hne and JZ9urD7PNClDZ1bm

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

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

scripts/test-jmespath-validation.ts

@@ -0,0 +1,114 @@
+#!/usr/bin/env npx tsx
+
+import { EnhancedConfigValidator } from '../src/services/enhanced-config-validator.js';
+
+console.log('🧪 Testing JMESPath Validation\n');
+
+const testCases = [
+  {
+    name: 'JMESPath with unquoted numeric literal',
+    config: {
+      language: 'javaScript',
+      jsCode: `const data = { users: [{ name: 'John', age: 30 }, { name: 'Jane', age: 25 }] };
+const adults = $jmespath(data, 'users[?age >= 18]');
+return [{json: {adults}}];`
+    },
+    expectError: true
+  },
+  {
+    name: 'JMESPath with properly quoted numeric literal',
+    config: {
+      language: 'javaScript',
+      jsCode: `const data = { users: [{ name: 'John', age: 30 }, { name: 'Jane', age: 25 }] };
+const adults = $jmespath(data, 'users[?age >= \`18\`]');
+return [{json: {adults}}];`
+    },
+    expectError: false
+  },
+  {
+    name: 'Multiple JMESPath filters with unquoted numbers',
+    config: {
+      language: 'javaScript',
+      jsCode: `const products = items.map(item => item.json);
+const expensive = $jmespath(products, '[?price > 100]');
+const lowStock = $jmespath(products, '[?quantity < 10]');
+const highPriority = $jmespath(products, '[?priority == 1]');
+return [{json: {expensive, lowStock, highPriority}}];`
+    },
+    expectError: true
+  },
+  {
+    name: 'JMESPath with string comparison (no backticks needed)',
+    config: {
+      language: 'javaScript',
+      jsCode: `const data = { users: [{ name: 'John', status: 'active' }, { name: 'Jane', status: 'inactive' }] };
+const activeUsers = $jmespath(data, 'users[?status == "active"]');
+return [{json: {activeUsers}}];`
+    },
+    expectError: false
+  },
+  {
+    name: 'Python JMESPath with unquoted numeric literal',
+    config: {
+      language: 'python',
+      pythonCode: `data = { 'users': [{ 'name': 'John', 'age': 30 }, { 'name': 'Jane', 'age': 25 }] }
+adults = _jmespath(data, 'users[?age >= 18]')
+return [{'json': {'adults': adults}}]`
+    },
+    expectError: true
+  },
+  {
+    name: 'Complex filter with decimal numbers',
+    config: {
+      language: 'javaScript',
+      jsCode: `const items = [{ price: 99.99 }, { price: 150.50 }, { price: 200 }];
+const expensive = $jmespath(items, '[?price >= 99.95]');
+return [{json: {expensive}}];`
+    },
+    expectError: true
+  }
+];
+
+let passCount = 0;
+let failCount = 0;
+
+for (const test of testCases) {
+  console.log(`Test: ${test.name}`);
+  const result = EnhancedConfigValidator.validateWithMode(
+    'nodes-base.code',
+    test.config,
+    [
+      { name: 'language', type: 'options', options: ['javaScript', 'python'] },
+      { name: 'jsCode', type: 'string' },
+      { name: 'pythonCode', type: 'string' }
+    ],
+    'operation',
+    'strict'
+  );
+  
+  const hasJMESPathError = result.errors.some(e => 
+    e.message.includes('JMESPath numeric literal') || 
+    e.message.includes('must be wrapped in backticks')
+  );
+  
+  const passed = hasJMESPathError === test.expectError;
+  
+  console.log(`  Expected error: ${test.expectError}`);
+  console.log(`  Has JMESPath error: ${hasJMESPathError}`);
+  console.log(`  Result: ${passed ? '✅ PASS' : '❌ FAIL'}`);
+  
+  if (result.errors.length > 0) {
+    console.log(`  Errors: ${result.errors.map(e => e.message).join(', ')}`);
+  }
+  if (result.warnings.length > 0) {
+    console.log(`  Warnings: ${result.warnings.slice(0, 2).map(w => w.message).join(', ')}`);
+  }
+  
+  if (passed) passCount++;
+  else failCount++;
+  
+  console.log();
+}
+
+console.log(`\n📊 Results: ${passCount} passed, ${failCount} failed`);
+console.log(failCount === 0 ? '✅ All JMESPath validation tests passed!' : '❌ Some tests failed');