chore: issue tracker rev20

- 55 open (was 54 at rev19). New: #265, #267, #268, #269. Closed: #244.
- Fixes on main: hallucination filter bundle, scene-detect flag (#269), docs
- Responded to #246, #247, #250, #233, #259, #269. All NEEDS RESPONSE cleared.
- #263, #267: requested debug logs + short file tests (cause unknown)
- Added Emerging Patterns section with factual symptom-only descriptions
- Updated roadmap: post-translation hallucination filter (P1), Thai/Korean targets

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: meizhong986