Harden pricelist formation and document architecture decisions

bible/history.md

@@ -5,6 +5,51 @@
 
 ---
 
+## 2026-02-20: Pricelist Formation Hardening (Estimate/Warehouse/Meta)
+
+### Decision
+
+Hardened pricelist formation rules to remove ambiguity and prevent silent data loss in UI/API.
+
+### What changed
+
+- `estimate` snapshot now explicitly excludes hidden components (`qt_lot_metadata.is_hidden = 1`).
+- Category snapshot in `qt_pricelist_items.lot_category` now always has a deterministic fallback:
+  `PART_` is assigned even when a LOT row is missing in `lot`.
+- `PricelistItem` JSON contract was normalized to a single category field
+  (`LotCategory -> json:"category"`), removing duplicate JSON-tag ambiguity.
+- Meta-price source expansion now always includes the base LOT, then merges `meta_prices`
+  sources with deduplication (exact + wildcard overlaps).
+
+### Rationale
+
+- Prevent hidden/ignored components from leaking into estimate pricelists.
+- Keep frontend category rendering stable for all items.
+- Avoid non-deterministic JSON serialization when duplicate tags are present.
+- Ensure meta-article pricing includes self-history and does not overcount duplicate sources.
+
+### Constraints
+
+- `estimate` pricelist invariant: `current_price > 0 AND is_hidden = 0`.
+- `category` in API must map from persisted `qt_pricelist_items.lot_category`.
+- Missing category source must default to `PART_`.
+- Meta source list must contain each LOT at most once.
+
+### Files
+
+- Model: `internal/models/pricelist.go`
+- Estimate/Warehouse snapshot service: `internal/services/pricelist/service.go`
+- Pricing handler/meta expansion: `internal/handlers/pricing.go`
+- Pricing service/meta expansion: `internal/services/pricing/service.go`
+- Tests:
+  - `internal/services/pricelist/service_estimate_test.go`
+  - `internal/services/pricelist/service_warehouse_test.go`
+  - `internal/handlers/pricing_meta_expand_test.go`
+  - `internal/services/pricing/service_meta_test.go`
+  - `internal/services/stock_import_test.go`
+
+---
+
 ## 2026-02-20: Seen Registry Deduplication by Partnumber
 
 ### Decision