- Section/subsection headings now appear in BOTH heading_events and
emitted_block_events (emitted_as='heading') for complete event stream
- Backmatter headings (Funding/Acknowledgments/Data Availability/Conflicts)
now generate heading_events → appear as structure tree sections with
their own body_units
- Page-qualified block IDs (p{page}:{block_id}) in tree own/subtree_block_ids
and body_units block_map: eliminates ambiguous block_id collisions when
same block_id appears on multiple pages in real OCR data
- TC-9.2 wording fix, KEYS empty guard, global unit_id uniqueness check
- RenderOutput dataclass with heading_events/emitted_block_events tracking
- Stack-algorithm structure tree with own/subtree block IDs
- Recursive body_units builder with role helper + token cap splitting
- Schema v4: section_path_json, section_level, section_title, part_ordinal
- Phase 4/5 reorder in ocr_rebuild.py and ocr.py
- 12 new test cases for tree nesting, own_block_ids, rendered-order intervals
