Introduce detailed console logging across document parsing API routes and worker
operation state fetches. Logs now capture stream openings, error conditions,
worker state unavailability, and invalid responses, improving observability and
debuggability for PDF parsing and ONNX layout processing flows.
Add worker operation state polling to document parse routes, enabling real-time
status and progress updates from the ONNX layout worker. Introduce
`fetchWorkerOperationState` utility and status mapping logic to synchronize
parse status with worker job state, improving accuracy for pending, running,
and failed operations.
