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>

internal/services/sync/partnumber_books.go

@@ -0,0 +1,92 @@
+package sync
+
+import (
+	"fmt"
+	"log/slog"
+	"time"
+
+	"git.mchus.pro/mchus/quoteforge/internal/localdb"
+	"git.mchus.pro/mchus/quoteforge/internal/repository"
+)
+
+// PullPartnumberBooks synchronizes partnumber book snapshots from MariaDB to local SQLite.
+// It only pulls books that don't exist locally yet (append-only).
+func (s *Service) PullPartnumberBooks() (int, error) {
+	slog.Info("starting partnumber book pull")
+
+	mariaDB, err := s.getDB()
+	if err != nil {
+		return 0, fmt.Errorf("database not available: %w", err)
+	}
+
+	localBookRepo := repository.NewPartnumberBookRepository(s.localDB.DB())
+
+	// Query server for all active partnumber books
+	type serverBook struct {
+		ID        int       `gorm:"column:id"`
+		Version   string    `gorm:"column:version"`
+		CreatedAt time.Time `gorm:"column:created_at"`
+		IsActive  bool      `gorm:"column:is_active"`
+	}
+	var serverBooks []serverBook
+	if err := mariaDB.Raw("SELECT id, version, created_at, is_active FROM qt_partnumber_books WHERE is_active = 1 ORDER BY created_at DESC, id DESC").Scan(&serverBooks).Error; err != nil {
+		return 0, fmt.Errorf("querying server partnumber books: %w", err)
+	}
+
+	pulled := 0
+	for _, sb := range serverBooks {
+		// Check if already exists locally
+		var existing localdb.LocalPartnumberBook
+		err := s.localDB.DB().Where("server_id = ?", sb.ID).First(&existing).Error
+		if err == nil {
+			// Already exists
+			continue
+		}
+
+		// Save the book
+		localBook := &localdb.LocalPartnumberBook{
+			ServerID:  sb.ID,
+			Version:   sb.Version,
+			CreatedAt: sb.CreatedAt,
+			IsActive:  sb.IsActive,
+		}
+		if err := localBookRepo.SaveBook(localBook); err != nil {
+			slog.Warn("failed to save local partnumber book", "server_id", sb.ID, "error", err)
+			continue
+		}
+
+		// Pull items for this book
+		type serverItem struct {
+			Partnumber  string `gorm:"column:partnumber"`
+			LotName     string `gorm:"column:lot_name"`
+			IsPrimaryPN bool   `gorm:"column:is_primary_pn"`
+			Description string `gorm:"column:description"`
+		}
+		var serverItems []serverItem
+		if err := mariaDB.Raw("SELECT partnumber, lot_name, is_primary_pn, description FROM qt_partnumber_book_items WHERE book_id = ?", sb.ID).Scan(&serverItems).Error; err != nil {
+			slog.Warn("failed to query server partnumber book items", "book_id", sb.ID, "error", err)
+			continue
+		}
+
+		localItems := make([]localdb.LocalPartnumberBookItem, 0, len(serverItems))
+		for _, si := range serverItems {
+			localItems = append(localItems, localdb.LocalPartnumberBookItem{
+				BookID:      localBook.ID,
+				Partnumber:  si.Partnumber,
+				LotName:     si.LotName,
+				IsPrimaryPN: si.IsPrimaryPN,
+				Description: si.Description,
+			})
+		}
+		if err := localBookRepo.SaveBookItems(localItems); err != nil {
+			slog.Warn("failed to save local partnumber book items", "book_id", localBook.ID, "error", err)
+			continue
+		}
+
+		slog.Info("pulled partnumber book", "version", sb.Version, "items", len(localItems))
+		pulled++
+	}
+
+	slog.Info("partnumber book pull completed", "pulled", pulled)
+	return pulled, nil
+}