# Task 11 — Export: JSON

## Goal
Two JSON products from the frozen canonical snapshot.

## Input
- `canonical/` snapshot, `schema/` (Tasks 09–10).

## Actions
1. Write `scripts/export_json.py` (streaming writer; never build the whole document in memory).
2. **Mega-file** `exports/json/dataset.json`: full hierarchy `data_note → batches → coupons(die) → samples → measurements → points`, plus embedded `data_dictionary` and `instruments`.
3. **Split set** `exports/json/split/`: directory mirrors the hierarchy; one file per measurement (points inline), plus `index.json` per level.
4. Each measurement object carries its lineage block `{source_file, mapping_version, schema_version}`.

## Intermediate Result (done when)
- Both products written; spot-validation: point counts per measurement match canonical.
- `exports/json/EXPORT_MANIFEST.json` written (snapshot id, versions, counts).
