# Step 0: sample-metadata-contract

## Read First
- /AGENTS.md
- /PLAN.md
- /PROGRESS.md
- /docs/HARNESS.md
- /docs/PRD.md
- /docs/ARCHITECTURE.md
- /docs/CONVERSION_POLICY.md
- /docs/ADR.md
- /docs/TOOLCHAIN.md

## Task
Create the first sample corpus metadata contract without implementing the conversion engine.

The metadata must classify every PDF currently under `samples/` by traits that future regression tests can use:
- text layer quality
- scanned or mixed scanned/text pages
- multi-column or complex layout risk
- formula density
- table density
- figure density
- Korean filename/path coverage
- target regression focus

Use deterministic JSON so future agents can update it with minimal diff noise.

## Sprint Contract
- Done means: `samples/metadata.json` exists, includes every current PDF by exact relative path, and has enough structured fields for future tests to select OCR, layout, formula, table, figure, and Korean-path cases.
- Hard thresholds:
  - Every current `samples/*.pdf` appears exactly once.
  - Metadata is valid UTF-8 JSON.
  - Tests fail if a sample PDF is added without metadata.
  - Tests fail if duplicate sample paths exist in the metadata.
  - No conversion engine code is introduced in this step.
- Files owned:
  - `samples/metadata.json`
  - `tests/test_sample_metadata.py`
  - `PROGRESS.md`
  - `phases/0-harness-foundation/index.json`
- Dependencies:
  - Existing sample PDFs under `samples/`
  - PyMuPDF may be used only for lightweight page count/text/image inspection if needed.

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

## Verification
1. Run the acceptance commands.
2. Confirm `samples/metadata.json` paths match `samples/*.pdf`.
3. Confirm Korean filenames remain readable in JSON.
4. Update `PROGRESS.md` with completed work, validation output, and next handoff.
5. Update this phase index step to `completed` with a one-line `summary`, or to `blocked`/`error` with a concrete reason.

## Do Not
- Do not create `src/` or conversion engine modules in this step.
- Do not rename, delete, compress, or rewrite sample PDFs.
- Do not add sidecar output files for converted documents.
- Do not add a new custom agent.