# Step 0: reading-order-checks

## Read First
- /AGENTS.md
- /PLAN.md
- /PROGRESS.md
- /docs/HARNESS.md
- /docs/IMPLEMENTATION_PLAN.md
- /docs/ARCHITECTURE.md
- /docs/CONVERSION_POLICY.md
- /phases/2-marker-adapter/step2.md

## Task
Create reading-order verification helpers over normalized blocks.

Use page numbers and bounding boxes to detect obvious ordering anomalies in multi-column or inserted-text layouts.

## Sprint Contract
- Done means: reading-order checks produce diagnostics that later enrichment and evaluator steps can use.
- Hard thresholds: checks are deterministic; tests include a multi-column-like fixture; helpers do not reorder content silently.
- Files owned: `src/pdftomd/enrichment.py`, tests, `PROGRESS.md`, `phases/4-semantic-enrichment/index.json`.
- Dependencies: Phase 2 normalized block model.

## Acceptance Criteria
```powershell
python scripts\validate_workspace.py
.\venv\python.exe -m pytest tests
```

## Verification
1. Run the acceptance commands.
2. Confirm diagnostics are actionable and tied to page/block ids.
3. Update `PROGRESS.md` and this phase index.

## Do Not
- Do not override Marker ordering without tests.
- Do not render Markdown.
- Do not call Marker or Nougat.
