Add jobs stats to /health; document parse_mode fast vs quality tradeoff

Self-keepalive while jobs are in flight to prevent autosleep mid-parse

Add job-style /parse/jobs API: submit-and-poll, durable across restarts

Stream /parse as NDJSON: heartbeat every 5s, terminal result event last

Pass llm_service as dotted-string path, not as ClaudeService instance

Fix quality mode 500: pass ClaudeService instance to PdfConverter

Add a friendly GET / root route

Scaffold marker: FastAPI wrapper around marker-pdf for HF Space