feat: implement vendor spec BOM import and PN→LOT resolution (Phase 1)

- Migration 029: local_partnumber_books, local_partnumber_book_items,
  vendor_spec TEXT column on local_configurations
- Models: LocalPartnumberBook, LocalPartnumberBookItem, VendorSpec,
  VendorSpecItem with JSON Valuer/Scanner
- Repository: PartnumberBookRepository (GetActiveBook, FindLotByPartnumber,
  SaveBook/Items, ListBooks, CountBookItems)
- Service: VendorSpecResolver 3-step resolution (book → manual suggestion
  → unresolved) + AggregateLOTs with is_primary_pn qty logic
- Sync: PullPartnumberBooks append-only pull from qt_partnumber_books
- Handlers: VendorSpecHandler (GET/PUT/resolve/apply), PartnumberBooksHandler
- Routes: /api/configs/:uuid/vendor-spec*, /api/partnumber-books,
  /api/sync/partnumber-books, /partnumber-books page
- UI: 3 top-level tabs [Estimate][BOM вендора][Ценообразование]; Excel paste,
  PN resolution, inline LOT autocomplete, pricing table
- Bible: 03-database.md updated, 09-vendor-spec.md added

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bible/03-database.md

@@ -21,11 +21,22 @@ File: `qfs.db` in the user-state directory (see [05-config.md](05-config.md)).
 | `local_pricelists` | Pricelist headers | `id`, `server_id` (unique), `source`, `version`, `created_at` |
 | `local_pricelist_items` | Pricelist line items ← **sole source of prices** | `id`, `pricelist_id` (FK), `lot_name`, `price`, `lot_category` |
 
+#### Partnumber Books (PN → LOT mapping, pull-only from PriceForge)
+
+| Table | Purpose | Key Fields |
+|-------|---------|------------|
+| `local_partnumber_books` | Version snapshots of PN→LOT mappings | `id`, `server_id` (unique), `version`, `created_at`, `is_active` |
+| `local_partnumber_book_items` | PN→LOT mapping rows | `id`, `book_id` (FK), `partnumber`, `lot_name`, `is_primary_pn` |
+
+Active book: `WHERE is_active=1 ORDER BY created_at DESC, id DESC LIMIT 1`
+
+`is_primary_pn=1` means this PN's quantity in the vendor BOM determines qty(LOT). If only non-primary PNs are present for a LOT, qty defaults to 1.
+
 #### Configurations and Projects
 
 | Table | Purpose | Key Fields |
 |-------|---------|------------|
-| `local_configurations` | Saved configurations | `id`, `uuid` (unique), `items` (JSON), `line_no`, `pricelist_id`, `warehouse_pricelist_id`, `competitor_pricelist_id`, `current_version_id`, `sync_status` |
+| `local_configurations` | Saved configurations | `id`, `uuid` (unique), `items` (JSON), `vendor_spec` (JSON), `line_no`, `pricelist_id`, `warehouse_pricelist_id`, `competitor_pricelist_id`, `current_version_id`, `sync_status` |
 | `local_configuration_versions` | Immutable snapshots (revisions) | `id`, `configuration_id` (FK), `version_no`, `data` (JSON), `change_note`, `created_at` |
 | `local_projects` | Projects | `id`, `uuid` (unique), `name`, `code`, `sync_status` |