Summary

Implement Notion → local for shuttle notion ingest.

Parent: #2

Scope

• Query all pages in notion.database_id
• Map properties using notion.properties config
• Convert page blocks → markdown body
• Write task_directory/{id}.md with YAML frontmatter
• Deterministic output (sorted, stable formatting)

Auth

• NOTION_TOKEN — read content, read database

Verification

• shuttle notion ingest writes one file per task
• Re-run without board changes produces identical files
• Unit tests with mocked Notion API responses

Execution

@gh-issue-execute → notion_sync.export_tasks → @gh-pr