Implement independent error storage system and comprehensive improvements

Major Features:
• Add persistent error tracking for timeout/network failures that bypasses PayloadCMS output limitations
• Implement smart error classification (timeout, DNS, connection, network) with duration-based detection
• Add comprehensive test infrastructure with MongoDB in-memory testing and enhanced mocking
• Fix HTTP request handler error preservation with detailed context storage
• Add independent execution tracking with success/failure status and duration metrics

Technical Improvements:
• Update JSONPath documentation to use correct $.trigger.doc syntax across all step types
• Fix PayloadCMS job execution to use runByID instead of run() for reliable task processing
• Add enhanced HTTP error handling that preserves outputs for 4xx/5xx status codes
• Implement proper nock configuration with undici for Node.js 22 fetch interception
• Add comprehensive unit tests for WorkflowExecutor with mocked PayloadCMS instances

Developer Experience:
• Add detailed error information in workflow context with URL, method, timeout, attempts
• Update README with HTTP error handling patterns and enhanced error tracking examples
• Add test helpers and setup infrastructure for reliable integration testing
• Fix workflow step validation and JSONPath field descriptions

Breaking Changes: None - fully backward compatible

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

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

test-results/.last-run.json

@@ -0,0 +1,4 @@
+{
+  "status": "failed",
+  "failedTests": []
+}