The ASHP bundle is priced from the rate sheet (ADR-0025); the catalogue
row is read only for its material id, which is nullable end-to-end. The
live `material` catalogue has no `air_source_heat_pump` row, so
`products.get` raised `ValueError: no active product` and aborted every
ASHP-eligible property.
Add `ProductNotFound(ValueError)` + a concrete `ProductRepository
.get_optional`, raise the typed error from both repos, and have
`_ashp_option` look the row up optionally — a missing row now yields an
ASHP Option with `material_id=None` rather than crashing.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>