Resolves the v1 simplification where every species cost the same.
- CutItem/StockPiece gain `material`; build_cut_plan and reoptimize group by
(stock, material) so each bought stick/sheet is a single species; pieces are
stamped with their material (offcut seeds keep theirs).
- prices.estimate groups by (stock, species) and applies a per-species
multiplier (DEFAULT_MATERIAL_MULTIPLIERS: SPF 1.0, oak 3.0, walnut 5.5, …),
persisted to material_multipliers.json. CostLine shows "oak 1x4".
- PriceEditDialog gains a species-multiplier table; BOM Buy list shows species.
- Offcuts carry material so offcut reuse matches species.
- tests: multiplier scales price, default species at base, mixed species on the
same stock priced separately, multiplier save/load.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
rob
36d02fcb73