Fix vendor mapping delete behavior and update docs

bible/api.md

@@ -61,7 +61,7 @@
 | POST | `/api/admin/pricing/recalculate-all` | Recalculate all prices (returns task_id) |
 | GET | `/api/admin/pricing/lots` | LOT list |
 | GET/POST | `/api/admin/pricing/stock-mappings` | Stock partnumber mappings |
-| GET/POST | `/api/admin/pricing/vendor-mappings` | Vendor partnumber mappings |
+| GET/POST/DELETE | `/api/admin/pricing/vendor-mappings` | Vendor partnumber mappings (DELETE removes mapping and seen-row from global list) |
 | GET | `/api/admin/pricing/alerts` | Alerts list |
 | GET  | `/api/admin/pricing/partnumber-books` | List all partnumber book snapshots with item counts |
 | POST | `/api/admin/pricing/partnumber-books` | Create partnumber book snapshot (returns task_id) |

bible/history.md

@@ -147,6 +147,12 @@ Implemented global vendor partnumber → LOT mapping with bundle support and see
 - Supports complex assembled vendor SKUs without client-side changes.
 - Centralizes ignore behavior across all sources via seen-registry.
 
+### Update (2026-02-25)
+
+- `DELETE /api/admin/pricing/vendor-mappings` now removes both:
+- mapping rows from `lot_partnumbers`
+- and matching entries from `qt_vendor_partnumber_seen` (so "seen/unmapped" rows disappear from the global UI immediately after delete).
+
 ### Constraints
 
 - Bundle LOT is internal and must stay hidden in regular LOT list by default.