# BAT-012 Design

## Architecture summary
- Introduce `jarca_ledger_mcp/application/imports_service.py` as the single application-layer home for import preview/import/rollback orchestration.
- Introduce `jarca_ledger_mcp/infrastructure/parsers/` as the parser seam so application code no longer imports top-level parser implementations directly.
- Keep current top-level parser modules for compatibility if needed, but route application/shared usage through the infrastructure seam.
- Preserve `application/import_transfer_services.py` as the advanced workflow home; import-facing public functions become delegations into `imports_service.py`.

## Changed areas
- application import orchestration
- infrastructure parser seam
- service export surface / compatibility proxy
- import regression verification docs

## Key decisions
1. Parser relocation is seam-first, not algorithm rewrite.
2. Import account auto-linking/classification stays in the application layer, not in parser modules.
3. Public API/tool names remain unchanged.

## Verification focus
- Import preview/import/rollback regression
- Evidence field preservation
- No breakage in MCP discovery and public exports