Fix JSON circular reference serialization and use PayloadCMS generated types

- Replace duplicate type definitions with PayloadCMS generated types
- Fix workflow context serialization with safeSerialize() method
- Resolve type mismatches (id: string vs number)
- Update all imports to use PayloadWorkflow type
- Ensure workflow runs are created successfully without serialization errors

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

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

package.json

@@ -85,6 +85,7 @@
     "react-dom": "19.1.0",
     "rimraf": "3.0.2",
     "sharp": "0.34.3",
+    "tsx": "^4.20.5",
     "typescript": "5.7.3",
     "vitest": "^3.1.2"
   },