feat: 数据概览/操作日志/批量操作 + 首页合格档案数

后台新增「数据概览」(商品/合格/按状态/品牌/分类/待审核) 与「操作日志」(全局审计分页)；商品列表支持多选批量改状态/分类。公开首页标题改为「天工」并展示合格档案数；新增公开接口 /api/v1/stats 与后台 /api/stats、/api/audit、/api/products/bulk。合格口径=quality_score≥0.6 且在用。

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

api/internal/adminhandler/handler.go

@@ -64,8 +64,11 @@ func (h *Handler) Router() http.Handler {
 		r.Group(func(r chi.Router) {
 			r.Use(h.authn.Middleware)
 			r.Get("/api/me", h.Me)
+			r.Get("/api/stats", h.Stats)
+			r.Get("/api/audit", h.ListAllAudit)
 			r.Get("/api/products", h.ListProducts)
 			r.Post("/api/products", h.CreateProduct)
+			r.Post("/api/products/bulk", h.BulkProducts)
 			r.Get("/api/products/{id}", h.GetProduct)
 			r.Put("/api/products/{id}", h.UpdateProduct)
 			r.Get("/api/products/{id}/audit", h.ListAudit)
@@ -203,6 +206,76 @@ func (h *Handler) CreateProduct(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusCreated, d)
 }
 
+// Stats returns the dashboard overview counters.
+func (h *Handler) Stats(w http.ResponseWriter, r *http.Request) {
+	st, err := h.store.Stats(r.Context())
+	if h.handleErr(w, err) {
+		return
+	}
+	writeJSON(w, http.StatusOK, st)
+}
+
+// ListAllAudit returns a page of the global operations audit log.
+func (h *Handler) ListAllAudit(w http.ResponseWriter, r *http.Request) {
+	page, size := pageParams(r)
+	items, total, err := h.store.ListAllAudit(r.Context(), size, (page-1)*size)
+	if h.handleErr(w, err) {
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]any{
+		"items": items, "page": page, "size": size, "total": total,
+	})
+}
+
+type bulkInput struct {
+	IDs        []string `json:"ids"`
+	Action     string   `json:"action"`
+	Status     string   `json:"status"`
+	CategoryID *string  `json:"category_id"`
+}
+
+// BulkProducts applies a status or category change to many products at once.
+func (h *Handler) BulkProducts(w http.ResponseWriter, r *http.Request) {
+	var in bulkInput
+	if err := json.NewDecoder(r.Body).Decode(&in); err != nil {
+		writeError(w, http.StatusBadRequest, "bad_request", "invalid body")
+		return
+	}
+	if len(in.IDs) == 0 {
+		writeError(w, http.StatusBadRequest, "bad_request", "未选择任何商品")
+		return
+	}
+	actor := auth.UserFrom(r.Context())
+	var (
+		affected int
+		err      error
+	)
+	switch in.Action {
+	case "status":
+		affected, err = h.store.BulkSetStatus(r.Context(), actor, in.IDs, in.Status)
+	case "category":
+		affected, err = h.store.BulkSetCategory(r.Context(), actor, in.IDs, in.CategoryID)
+	default:
+		writeError(w, http.StatusBadRequest, "bad_request", "未知的批量操作")
+		return
+	}
+	switch {
+	case errors.Is(err, adminstore.ErrInvalidStatus):
+		writeError(w, http.StatusBadRequest, "invalid_status", "无效的状态值")
+		return
+	case errors.Is(err, adminstore.ErrInvalidParent):
+		writeError(w, http.StatusBadRequest, "invalid_parent", "目标分类无效")
+		return
+	case errors.Is(err, adminstore.ErrNoTargets):
+		writeError(w, http.StatusBadRequest, "bad_request", "未选择任何商品")
+		return
+	}
+	if h.handleErr(w, err) {
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]any{"status": "ok", "affected": affected})
+}
+
 // UpdateProduct applies an edit.
 func (h *Handler) UpdateProduct(w http.ResponseWriter, r *http.Request) {
 	var in adminstore.ProductInput