feat: сохранять ручные PN→LOT маппинги как lot_suggestion в qt_vendor_partnumber_seen

При сохранении vendor-spec строки с заполненным lot_mappings автоматически
отправляются на сервер и пишутся в новый столбец lot_suggestion. Столбец
хранит JSON-массив [{lot_name, qty}] — тот же формат, что qt_partnumber_book_items.lots_json.

Если миграция ещё не прошла (столбец отсутствует), приложение логирует WARN
и записывает строку без столбца; сбоя нет.

Контракт для инструмента создания partnumber-books описан в bible-local/11-lot-suggestions.md.

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

internal/handlers/vendor_spec.go

@@ -9,6 +9,7 @@ import (
 	"git.mchus.pro/mchus/quoteforge/internal/localdb"
 	"git.mchus.pro/mchus/quoteforge/internal/repository"
 	"git.mchus.pro/mchus/quoteforge/internal/services"
+	syncsvc "git.mchus.pro/mchus/quoteforge/internal/services/sync"
 	"github.com/gin-gonic/gin"
 )
 
@@ -16,12 +17,14 @@ import (
 type VendorSpecHandler struct {
 	localDB       *localdb.LocalDB
 	configService *services.LocalConfigurationService
+	syncService   *syncsvc.Service // optional; nil = no server push
 }
 
-func NewVendorSpecHandler(localDB *localdb.LocalDB) *VendorSpecHandler {
+func NewVendorSpecHandler(localDB *localdb.LocalDB, syncService *syncsvc.Service) *VendorSpecHandler {
 	return &VendorSpecHandler{
 		localDB:       localDB,
 		configService: services.NewLocalConfigurationService(localDB, nil, nil, func() bool { return false }),
+		syncService:   syncService,
 	}
 }
 
@@ -111,9 +114,57 @@ func (h *VendorSpecHandler) PutVendorSpec(c *gin.Context) {
 		return
 	}
 
+	// Push manual lot mappings as suggestions to the server (best-effort, non-blocking).
+	h.pushLotSuggestions(body.VendorSpec)
+
 	c.JSON(http.StatusOK, gin.H{"vendor_spec": spec})
 }
 
+// pushLotSuggestions sends manual PN→LOT mappings to qt_vendor_partnumber_seen.lot_suggestion.
+// Errors are logged and silently dropped — they must not affect the HTTP response.
+func (h *VendorSpecHandler) pushLotSuggestions(spec []localdb.VendorSpecItem) {
+	if h.syncService == nil {
+		return
+	}
+
+	var items []syncsvc.SeenPartnumber
+	for _, row := range spec {
+		if row.VendorPartnumber == "" || len(row.LotMappings) == 0 {
+			continue
+		}
+		suggestion := make([]syncsvc.LotSuggestionEntry, 0, len(row.LotMappings))
+		for _, m := range row.LotMappings {
+			if m.LotName == "" {
+				continue
+			}
+			qty := m.QuantityPerPN
+			if qty < 1 {
+				qty = 1
+			}
+			suggestion = append(suggestion, syncsvc.LotSuggestionEntry{
+				LotName: m.LotName,
+				Qty:     qty,
+			})
+		}
+		if len(suggestion) == 0 {
+			continue
+		}
+		items = append(items, syncsvc.SeenPartnumber{
+			Partnumber:    row.VendorPartnumber,
+			Description:   row.Description,
+			LotSuggestion: suggestion,
+		})
+	}
+
+	if len(items) == 0 {
+		return
+	}
+
+	if err := h.syncService.PushPartnumberSeen(items); err != nil {
+		slog.Warn("vendor_spec: failed to push lot suggestions to server", "error", err)
+	}
+}
+
 func normalizeLotMappings(in []localdb.VendorSpecLotMapping) []localdb.VendorSpecLotMapping {
 	if len(in) == 0 {
 		return nil