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/handlers/web.go

@@ -67,7 +67,7 @@ func NewWebHandler(templatesPath string, componentService *services.ComponentSer
 	}
 
 	// Load each page template with base
-	simplePages := []string{"login.html", "configs.html", "projects.html", "project_detail.html", "pricelists.html", "pricelist_detail.html", "config_revisions.html"}
+	simplePages := []string{"login.html", "configs.html", "projects.html", "project_detail.html", "pricelists.html", "pricelist_detail.html", "config_revisions.html", "partnumber_books.html"}
 	for _, page := range simplePages {
 		pagePath := filepath.Join(templatesPath, page)
 		var tmpl *template.Template
@@ -212,6 +212,10 @@ func (h *WebHandler) PricelistDetail(c *gin.Context) {
 	h.render(c, "pricelist_detail.html", gin.H{"ActivePage": "pricelists"})
 }
 
+func (h *WebHandler) PartnumberBooks(c *gin.Context) {
+	h.render(c, "partnumber_books.html", gin.H{"ActivePage": "partnumber-books"})
+}
+
 // Partials for htmx
 
 func (h *WebHandler) ComponentsPartial(c *gin.Context) {