feat(progress): Redis live bar, SQLite for stage start/end

[nexus69420]

Summary

• Live done/ otal come from a Redis cache (pipeline:progress:{workflow_id}) that the worker updates on each activity heartbeat.
• SQLite stays canonical for stage start/end and finished page/chunk rows. The bar is hidden when SQLite leaves OCR/translation/chunking/ingest. No live ticker is written to document_jobs.config_json.
• Redis is an ephemeral UI ticker, not content SoT. Compose adds a
  edis service (not published). API + worker get REDIS_URL. Tests use the in-memory fallback when REDIS_URL is unset.
• Document Ops polls every 1s while a live stage is running.
• OCR default segment size is 5 pages (OCR_SEGMENT_PAGES) so the bar ticks during Chandra, not once at the end of a 20-page block.
• Ingest heartbeats include workflow_id so Redis actually updates during ingest.
• Translation remaining-work ticks use the event denominator (pages still to translate), not len(pages) or the language-detection total.

Test plan

• pytest tests/test_runtime_progress.py tests/test_activities.py::TestTranslationRetryProgressPersistence (43 passed)
• Worker heartbeat path moves OCR / translation / chunking / ingest bars, then hides them on review/completed
• Translation callback keeps event pages_total (remaining work), does not inflate to the full page set
• LIVE_PROGRESS_UI_ENABLED=true with Redis up on H100: bars move from cache, disappear when SQLite hits review
• Redis down: pipeline still runs; bar may stay at the SQLite start snapshot until Redis recovers
• Flag off: progress is null