Background tasks (ingestion, PDF resolution, scheduler) now acquire an
asyncio.Semaphore before checking out a DB connection, guaranteeing at
least N connections remain available for API request handlers. Removes
duplicate polling loop from PublicationsPage, debounces publication
reload on run-status changes, and increases poll interval from 5s to 15s
since SSE handles live discovery.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Rename _int_or_default → int_or_default (public API, was using private convention)
- Extract shared pdf_queue utilities (utcnow, event_row, queued_job, status constants) to pdf_queue_common.py to avoid circular imports
- Consolidate _effective_request_delay_seconds into queue_runner.py with explicit floor parameter
- Update tests to match new function locations and names
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>