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/repository/partnumber_book.go

@@ -0,0 +1,66 @@
+package repository
+
+import (
+	"git.mchus.pro/mchus/quoteforge/internal/localdb"
+	"gorm.io/gorm"
+)
+
+// PartnumberBookRepository provides read-only access to local partnumber book snapshots.
+type PartnumberBookRepository struct {
+	db *gorm.DB
+}
+
+func NewPartnumberBookRepository(db *gorm.DB) *PartnumberBookRepository {
+	return &PartnumberBookRepository{db: db}
+}
+
+// GetActiveBook returns the most recently active local partnumber book.
+func (r *PartnumberBookRepository) GetActiveBook() (*localdb.LocalPartnumberBook, error) {
+	var book localdb.LocalPartnumberBook
+	err := r.db.Where("is_active = 1").Order("created_at DESC, id DESC").First(&book).Error
+	if err != nil {
+		return nil, err
+	}
+	return &book, nil
+}
+
+// GetBookItems returns all items for the given local book ID.
+func (r *PartnumberBookRepository) GetBookItems(bookID uint) ([]localdb.LocalPartnumberBookItem, error) {
+	var items []localdb.LocalPartnumberBookItem
+	err := r.db.Where("book_id = ?", bookID).Find(&items).Error
+	return items, err
+}
+
+// FindLotByPartnumber looks up a partnumber in the active book and returns the matching items.
+func (r *PartnumberBookRepository) FindLotByPartnumber(bookID uint, partnumber string) ([]localdb.LocalPartnumberBookItem, error) {
+	var items []localdb.LocalPartnumberBookItem
+	err := r.db.Where("book_id = ? AND partnumber = ?", bookID, partnumber).Find(&items).Error
+	return items, err
+}
+
+// ListBooks returns all local partnumber books ordered newest first.
+func (r *PartnumberBookRepository) ListBooks() ([]localdb.LocalPartnumberBook, error) {
+	var books []localdb.LocalPartnumberBook
+	err := r.db.Order("created_at DESC, id DESC").Find(&books).Error
+	return books, err
+}
+
+// SaveBook saves a new partnumber book snapshot.
+func (r *PartnumberBookRepository) SaveBook(book *localdb.LocalPartnumberBook) error {
+	return r.db.Save(book).Error
+}
+
+// SaveBookItems bulk-inserts items for a book snapshot.
+func (r *PartnumberBookRepository) SaveBookItems(items []localdb.LocalPartnumberBookItem) error {
+	if len(items) == 0 {
+		return nil
+	}
+	return r.db.CreateInBatches(items, 500).Error
+}
+
+// CountBookItems returns the number of items for a given local book ID.
+func (r *PartnumberBookRepository) CountBookItems(bookID uint) int64 {
+	var count int64
+	r.db.Model(&localdb.LocalPartnumberBookItem{}).Where("book_id = ?", bookID).Count(&count)
+	return count
+}