feat(admin): 品牌管理 + 新建商品

品牌管理：列出品牌及引用商品数，支持改名、合并重复品牌（把源品牌的商品并入目标后删除源）、删除未被引用的品牌。新建商品：商品列表新增「新建商品」入口，填写名称/条码/品牌/品类后创建并进入详情页继续补全。

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

admin-frontend/src/App.tsx

@@ -6,9 +6,10 @@ import ProductDetail from "./components/ProductDetail";
 import SubmissionsPage from "./components/SubmissionsPage";
 import ApiKeysPage from "./components/ApiKeysPage";
 import CategoriesPage from "./components/CategoriesPage";
-import { FolderTree, Inbox, KeyRound, LogOut, Package } from "lucide-react";
+import BrandsPage from "./components/BrandsPage";
+import { FolderTree, Inbox, KeyRound, LogOut, Package, Tag } from "lucide-react";
 
-type Tab = "products" | "submissions" | "categories" | "keys";
+type Tab = "products" | "submissions" | "categories" | "brands" | "keys";
 type View = { name: "list" } | { name: "detail"; id: string };
 
 export default function App() {
@@ -114,6 +115,16 @@ export default function App() {
             >
               <FolderTree className="h-4 w-4" /> 分类管理
             </button>
+            <button
+              onClick={() => setTab("brands")}
+              className={`px-3 py-1.5 rounded-md flex items-center gap-1.5 ${
+                tab === "brands"
+                  ? "bg-emerald-50 text-emerald-700"
+                  : "text-gray-600 hover:bg-gray-100"
+              }`}
+            >
+              <Tag className="h-4 w-4" /> 品牌管理
+            </button>
             <button
               onClick={() => setTab("keys")}
               className={`px-3 py-1.5 rounded-md flex items-center gap-1.5 ${
@@ -141,6 +152,8 @@ export default function App() {
           <ApiKeysPage />
         ) : tab === "categories" ? (
           <CategoriesPage />
+        ) : tab === "brands" ? (
+          <BrandsPage />
         ) : tab === "submissions" ? (
           <SubmissionsPage onPending={setPending} />
         ) : view.name === "list" ? (

admin-frontend/src/api.ts

@@ -61,6 +61,11 @@ export const api = {
     }>(`/products?q=${encodeURIComponent(q)}&page=${page}&size=${size}`),
   getProduct: (id: string) =>
     request<import("./types").ProductDetail>(`/products/${id}`),
+  createProduct: (body: unknown) =>
+    request<import("./types").ProductDetail>("/products", {
+      method: "POST",
+      body: JSON.stringify(body),
+    }),
   updateProduct: (id: string, body: unknown) =>
     request<import("./types").ProductDetail>(`/products/${id}`, {
       method: "PUT",
@@ -102,6 +107,23 @@ export const api = {
     ),
   listBrands: () =>
     request<{ items: import("./types").Brand[] }>("/brands"),
+  createBrand: (name: string) =>
+    request<import("./types").Brand>("/brands", {
+      method: "POST",
+      body: JSON.stringify({ name }),
+    }),
+  updateBrand: (id: string, name: string) =>
+    request<import("./types").Brand>(`/brands/${id}`, {
+      method: "PUT",
+      body: JSON.stringify({ name }),
+    }),
+  mergeBrands: (id: string, targetId: string) =>
+    request<import("./types").Brand>(`/brands/${id}/merge`, {
+      method: "POST",
+      body: JSON.stringify({ target_id: targetId }),
+    }),
+  deleteBrand: (id: string) =>
+    request<{ status: string }>(`/brands/${id}`, { method: "DELETE" }),
   listCategories: () =>
     request<{ items: import("./types").Category[] }>("/categories"),
   createCategory: (body: import("./types").CategoryInput) =>

admin-frontend/src/components/BrandsPage.tsx

@@ -0,0 +1,305 @@
+import { useEffect, useMemo, useState } from "react";
+import { api, ApiError } from "../api";
+import type { Brand } from "../types";
+import { Tag, Pencil, Plus, Trash2, GitMerge, Search } from "lucide-react";
+
+type EditState = { id: string; name: string };
+type MergeState = { source: Brand; targetId: string };
+
+export default function BrandsPage() {
+  const [rows, setRows] = useState<Brand[]>([]);
+  const [error, setError] = useState("");
+  const [query, setQuery] = useState("");
+  const [creating, setCreating] = useState(false);
+  const [newName, setNewName] = useState("");
+  const [edit, setEdit] = useState<EditState | null>(null);
+  const [merge, setMerge] = useState<MergeState | null>(null);
+  const [busy, setBusy] = useState(false);
+
+  async function load() {
+    setError("");
+    try {
+      const res = await api.listBrands();
+      setRows(res.items);
+    } catch (e) {
+      setError(e instanceof ApiError ? e.message : "加载失败");
+    }
+  }
+
+  useEffect(() => {
+    load();
+  }, []);
+
+  const filtered = useMemo(() => {
+    const q = query.trim().toLowerCase();
+    if (!q) return rows;
+    return rows.filter((b) => b.name.toLowerCase().includes(q));
+  }, [rows, query]);
+
+  function fail(e: unknown, fallback: string) {
+    setError(e instanceof ApiError ? e.message : fallback);
+  }
+
+  async function create() {
+    if (!newName.trim()) return;
+    setBusy(true);
+    setError("");
+    try {
+      await api.createBrand(newName.trim());
+      setNewName("");
+      setCreating(false);
+      await load();
+    } catch (e) {
+      fail(e, "新建失败");
+    } finally {
+      setBusy(false);
+    }
+  }
+
+  async function saveEdit() {
+    if (!edit || !edit.name.trim()) return;
+    setBusy(true);
+    setError("");
+    try {
+      await api.updateBrand(edit.id, edit.name.trim());
+      setEdit(null);
+      await load();
+    } catch (e) {
+      fail(e, "保存失败");
+    } finally {
+      setBusy(false);
+    }
+  }
+
+  async function remove(b: Brand) {
+    if (!confirm(`确认删除品牌「${b.name}」？`)) return;
+    setError("");
+    try {
+      await api.deleteBrand(b.id);
+      await load();
+    } catch (e) {
+      fail(e, "删除失败");
+    }
+  }
+
+  async function doMerge() {
+    if (!merge || !merge.targetId) return;
+    const target = rows.find((b) => b.id === merge.targetId);
+    if (
+      !confirm(
+        `将「${merge.source.name}」的 ${merge.source.product_count} 个商品并入「${target?.name}」，并删除「${merge.source.name}」？`,
+      )
+    )
+      return;
+    setBusy(true);
+    setError("");
+    try {
+      await api.mergeBrands(merge.source.id, merge.targetId);
+      setMerge(null);
+      await load();
+    } catch (e) {
+      fail(e, "合并失败");
+    } finally {
+      setBusy(false);
+    }
+  }
+
+  return (
+    <div className="max-w-4xl">
+      <div className="flex items-center justify-between mb-4">
+        <div>
+          <h2 className="text-lg font-semibold text-gray-800 flex items-center gap-2">
+            <Tag className="h-5 w-5 text-emerald-600" /> 品牌管理
+          </h2>
+          <p className="text-sm text-gray-500 mt-1">
+            维护品牌名录。可重命名、删除未被引用的品牌，或将重复品牌合并到一起。
+          </p>
+        </div>
+        <button
+          onClick={() => {
+            setCreating(true);
+            setNewName("");
+          }}
+          className="px-4 py-2 rounded-lg bg-emerald-600 text-white text-sm font-medium hover:bg-emerald-700 flex items-center gap-1.5"
+        >
+          <Plus className="h-4 w-4" /> 新建品牌
+        </button>
+      </div>
+
+      {error && (
+        <div className="mb-3 bg-red-50 text-red-700 text-sm rounded px-4 py-2">{error}</div>
+      )}
+
+      <div className="mb-3 relative w-72">
+        <Search className="absolute left-2 top-2.5 h-4 w-4 text-gray-400" />
+        <input
+          value={query}
+          onChange={(e) => setQuery(e.target.value)}
+          placeholder="筛选品牌名"
+          className="w-full rounded border border-gray-300 py-2 pl-8 pr-3 text-sm focus:border-emerald-500 focus:outline-none"
+        />
+      </div>
+
+      {creating && (
+        <div className="mb-4 bg-white border rounded-lg p-5">
+          <h3 className="font-medium text-gray-700 mb-3">新建品牌</h3>
+          <div className="flex items-end gap-2">
+            <label className="block flex-1">
+              <span className="text-xs text-gray-500">品牌名称 *</span>
+              <input
+                autoFocus
+                className="w-full border rounded-md px-3 py-2 text-sm mt-1"
+                value={newName}
+                onChange={(e) => setNewName(e.target.value)}
+                onKeyDown={(e) => e.key === "Enter" && create()}
+                placeholder="例如：可口可乐"
+              />
+            </label>
+            <button
+              onClick={create}
+              disabled={busy}
+              className="px-4 py-2 rounded bg-emerald-600 text-white text-sm hover:bg-emerald-700 disabled:opacity-60"
+            >
+              保存
+            </button>
+            <button
+              onClick={() => setCreating(false)}
+              className="px-4 py-2 rounded border text-sm text-gray-600"
+            >
+              取消
+            </button>
+          </div>
+        </div>
+      )}
+
+      {merge && (
+        <div className="mb-4 bg-white border rounded-lg p-5">
+          <h3 className="font-medium text-gray-700 mb-3 flex items-center gap-1.5">
+            <GitMerge className="h-4 w-4 text-emerald-600" /> 合并品牌
+          </h3>
+          <p className="text-sm text-gray-500 mb-3">
+            把「{merge.source.name}」（{merge.source.product_count} 个商品）合并到下面选择的品牌，源品牌将被删除。
+          </p>
+          <div className="flex items-end gap-2">
+            <label className="block flex-1">
+              <span className="text-xs text-gray-500">合并到</span>
+              <select
+                className="w-full border rounded-md px-3 py-2 text-sm mt-1 bg-white"
+                value={merge.targetId}
+                onChange={(e) => setMerge({ ...merge, targetId: e.target.value })}
+              >
+                <option value="">（请选择目标品牌）</option>
+                {rows
+                  .filter((b) => b.id !== merge.source.id)
+                  .map((b) => (
+                    <option key={b.id} value={b.id}>
+                      {b.name}（{b.product_count}）
+                    </option>
+                  ))}
+              </select>
+            </label>
+            <button
+              onClick={doMerge}
+              disabled={busy || !merge.targetId}
+              className="px-4 py-2 rounded bg-emerald-600 text-white text-sm hover:bg-emerald-700 disabled:opacity-60"
+            >
+              合并
+            </button>
+            <button
+              onClick={() => setMerge(null)}
+              className="px-4 py-2 rounded border text-sm text-gray-600"
+            >
+              取消
+            </button>
+          </div>
+        </div>
+      )}
+
+      <div className="bg-white border rounded-lg overflow-hidden">
+        <table className="w-full text-sm">
+          <thead className="bg-gray-50 text-gray-500 text-left">
+            <tr>
+              <th className="px-4 py-2 font-medium">品牌</th>
+              <th className="px-4 py-2 font-medium">商品数</th>
+              <th className="px-4 py-2 font-medium"></th>
+            </tr>
+          </thead>
+          <tbody className="divide-y">
+            {filtered.length === 0 ? (
+              <tr>
+                <td colSpan={3} className="px-4 py-8 text-center text-gray-400">
+                  {rows.length === 0 ? "暂无品牌" : "无匹配品牌"}
+                </td>
+              </tr>
+            ) : (
+              filtered.map((b) => (
+                <tr key={b.id} className="hover:bg-gray-50">
+                  <td className="px-4 py-2 text-gray-800">
+                    {edit && edit.id === b.id ? (
+                      <input
+                        autoFocus
+                        className="border rounded px-2 py-1 text-sm w-64"
+                        value={edit.name}
+                        onChange={(e) => setEdit({ ...edit, name: e.target.value })}
+                        onKeyDown={(e) => {
+                          if (e.key === "Enter") saveEdit();
+                          if (e.key === "Escape") setEdit(null);
+                        }}
+                      />
+                    ) : (
+                      <span className="font-medium">{b.name}</span>
+                    )}
+                  </td>
+                  <td className="px-4 py-2 text-gray-600">{b.product_count}</td>
+                  <td className="px-4 py-2 text-right whitespace-nowrap">
+                    {edit && edit.id === b.id ? (
+                      <>
+                        <button
+                          onClick={saveEdit}
+                          disabled={busy}
+                          className="text-emerald-600 hover:text-emerald-700 text-xs mr-3"
+                        >
+                          保存
+                        </button>
+                        <button
+                          onClick={() => setEdit(null)}
+                          className="text-gray-400 hover:text-gray-600 text-xs"
+                        >
+                          取消
+                        </button>
+                      </>
+                    ) : (
+                      <>
+                        <button
+                          onClick={() => setEdit({ id: b.id, name: b.name })}
+                          className="text-gray-400 hover:text-emerald-600 mr-3"
+                          title="重命名"
+                        >
+                          <Pencil className="h-4 w-4" />
+                        </button>
+                        <button
+                          onClick={() => setMerge({ source: b, targetId: "" })}
+                          className="text-gray-400 hover:text-emerald-600 mr-3"
+                          title="合并到其它品牌"
+                        >
+                          <GitMerge className="h-4 w-4" />
+                        </button>
+                        <button
+                          onClick={() => remove(b)}
+                          className="text-gray-400 hover:text-red-600"
+                          title="删除"
+                        >
+                          <Trash2 className="h-4 w-4" />
+                        </button>
+                      </>
+                    )}
+                  </td>
+                </tr>
+              ))
+            )}
+          </tbody>
+        </table>
+      </div>
+    </div>
+  );
+}

admin-frontend/src/components/ProductList.tsx

@@ -1,7 +1,7 @@
 import { useEffect, useState } from "react";
-import { api } from "../api";
-import { FIELD_LABELS, ProductRow } from "../types";
-import { Search, AlertCircle } from "lucide-react";
+import { api, ApiError } from "../api";
+import { Brand, Category, FIELD_LABELS, ProductRow } from "../types";
+import { Search, AlertCircle, Plus } from "lucide-react";
 
 const STATUS_LABEL: Record<string, string> = {
   active: "在用",
@@ -37,6 +37,7 @@ export default function ProductList({
   const [total, setTotal] = useState(0);
   const [loading, setLoading] = useState(false);
   const [error, setError] = useState("");
+  const [creating, setCreating] = useState(false);
 
   useEffect(() => {
     setLoading(true);
@@ -79,9 +80,26 @@ export default function ProductList({
           <button className="rounded bg-emerald-600 px-3 py-2 text-sm text-white hover:bg-emerald-700">
             搜索
           </button>
+          <button
+            type="button"
+            onClick={() => setCreating(true)}
+            className="flex items-center gap-1 rounded bg-gray-700 px-3 py-2 text-sm text-white hover:bg-gray-800"
+          >
+            <Plus className="h-4 w-4" /> 新建商品
+          </button>
         </form>
       </div>
 
+      {creating && (
+        <CreateProductModal
+          onClose={() => setCreating(false)}
+          onCreated={(id) => {
+            setCreating(false);
+            onOpen(id);
+          }}
+        />
+      )}
+
       {error && (
         <div className="mb-3 rounded bg-red-50 px-3 py-2 text-sm text-red-600">
           {error}
@@ -176,3 +194,130 @@ export default function ProductList({
     </div>
   );
 }
+
+function CreateProductModal({
+  onClose,
+  onCreated,
+}: {
+  onClose: () => void;
+  onCreated: (id: string) => void;
+}) {
+  const [name, setName] = useState("");
+  const [gtin, setGtin] = useState("");
+  const [brand, setBrand] = useState("");
+  const [categoryId, setCategoryId] = useState("");
+  const [brands, setBrands] = useState<Brand[]>([]);
+  const [categories, setCategories] = useState<Category[]>([]);
+  const [busy, setBusy] = useState(false);
+  const [error, setError] = useState("");
+
+  useEffect(() => {
+    api.listBrands().then((r) => setBrands(r.items)).catch(() => {});
+    api.listCategories().then((r) => setCategories(r.items)).catch(() => {});
+  }, []);
+
+  async function submit() {
+    if (!name.trim()) {
+      setError("名称不能为空");
+      return;
+    }
+    setBusy(true);
+    setError("");
+    try {
+      const created = await api.createProduct({
+        name: name.trim(),
+        gtin: gtin.trim() || null,
+        brand_name: brand.trim() || null,
+        category_id: categoryId || null,
+        status: "active",
+      });
+      onCreated(created.id);
+    } catch (e) {
+      setError(e instanceof ApiError ? e.message : "新建失败");
+    } finally {
+      setBusy(false);
+    }
+  }
+
+  return (
+    <div className="fixed inset-0 z-20 flex items-center justify-center bg-black/30">
+      <div className="w-full max-w-md rounded-lg bg-white p-6 shadow-lg">
+        <h3 className="mb-4 text-base font-semibold text-gray-800">新建商品</h3>
+        {error && (
+          <div className="mb-3 rounded bg-red-50 px-3 py-2 text-sm text-red-600">
+            {error}
+          </div>
+        )}
+        <div className="space-y-3">
+          <label className="block">
+            <span className="text-xs text-gray-500">名称 *</span>
+            <input
+              autoFocus
+              className="mt-1 w-full rounded border border-gray-300 px-3 py-2 text-sm"
+              value={name}
+              onChange={(e) => setName(e.target.value)}
+              placeholder="商品名称"
+            />
+          </label>
+          <label className="block">
+            <span className="text-xs text-gray-500">条码 (GTIN，可选)</span>
+            <input
+              className="mt-1 w-full rounded border border-gray-300 px-3 py-2 text-sm"
+              value={gtin}
+              onChange={(e) => setGtin(e.target.value)}
+              placeholder="8/12/13/14 位"
+            />
+          </label>
+          <label className="block">
+            <span className="text-xs text-gray-500">品牌（不存在将自动创建，可选）</span>
+            <input
+              list="create-brand-list"
+              className="mt-1 w-full rounded border border-gray-300 px-3 py-2 text-sm"
+              value={brand}
+              onChange={(e) => setBrand(e.target.value)}
+            />
+            <datalist id="create-brand-list">
+              {brands.map((b) => (
+                <option key={b.id} value={b.name} />
+              ))}
+            </datalist>
+          </label>
+          <label className="block">
+            <span className="text-xs text-gray-500">品类（可选）</span>
+            <select
+              className="mt-1 w-full rounded border border-gray-300 bg-white px-3 py-2 text-sm"
+              value={categoryId}
+              onChange={(e) => setCategoryId(e.target.value)}
+            >
+              <option value="">（未分类）</option>
+              {categories.map((c) => (
+                <option key={c.id} value={c.id}>
+                  {"\u00A0".repeat(c.level * 2)}
+                  {c.name_zh} ({c.path})
+                </option>
+              ))}
+            </select>
+          </label>
+        </div>
+        <p className="mt-3 text-xs text-gray-400">
+          创建后将进入详情页，可继续补全营养、图片、多条码等信息。
+        </p>
+        <div className="mt-4 flex justify-end gap-2">
+          <button
+            onClick={onClose}
+            className="rounded border px-4 py-2 text-sm text-gray-600"
+          >
+            取消
+          </button>
+          <button
+            onClick={submit}
+            disabled={busy}
+            className="rounded bg-emerald-600 px-4 py-2 text-sm text-white hover:bg-emerald-700 disabled:opacity-60"
+          >
+            {busy ? "创建中…" : "创建并编辑"}
+          </button>
+        </div>
+      </div>
+    </div>
+  );
+}

admin-frontend/src/types.ts

@@ -66,6 +66,7 @@ export interface ProductDetail {
 export interface Brand {
   id: string;
   name: string;
+  product_count: number;
 }
 
 export interface Category {

api/internal/adminhandler/handler.go

@@ -65,6 +65,7 @@ func (h *Handler) Router() http.Handler {
 			r.Use(h.authn.Middleware)
 			r.Get("/api/me", h.Me)
 			r.Get("/api/products", h.ListProducts)
+			r.Post("/api/products", h.CreateProduct)
 			r.Get("/api/products/{id}", h.GetProduct)
 			r.Put("/api/products/{id}", h.UpdateProduct)
 			r.Get("/api/products/{id}/audit", h.ListAudit)
@@ -76,6 +77,10 @@ func (h *Handler) Router() http.Handler {
 			r.Delete("/api/products/{id}/barcodes/{barcodeID}", h.DeleteBarcode)
 			r.Post("/api/products/{id}/barcodes/{barcodeID}/primary", h.SetPrimaryBarcode)
 			r.Get("/api/brands", h.ListBrands)
+			r.Post("/api/brands", h.CreateBrand)
+			r.Put("/api/brands/{id}", h.UpdateBrand)
+			r.Post("/api/brands/{id}/merge", h.MergeBrands)
+			r.Delete("/api/brands/{id}", h.DeleteBrand)
 			r.Get("/api/categories", h.ListCategories)
 			r.Post("/api/categories", h.CreateCategory)
 			r.Put("/api/categories/{id}", h.UpdateCategory)
@@ -175,6 +180,29 @@ func (h *Handler) GetProduct(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, d)
 }
 
+// CreateProduct adds a new product with core fields; the rest is filled in via
+// the detail editor.
+func (h *Handler) CreateProduct(w http.ResponseWriter, r *http.Request) {
+	var in adminstore.ProductInput
+	if err := json.NewDecoder(r.Body).Decode(&in); err != nil {
+		writeError(w, http.StatusBadRequest, "bad_request", "invalid body")
+		return
+	}
+	if strings.TrimSpace(in.Name) == "" {
+		writeError(w, http.StatusBadRequest, "bad_request", "名称不能为空")
+		return
+	}
+	d, err := h.store.CreateProduct(r.Context(), auth.UserFrom(r.Context()), in)
+	if errors.Is(err, adminstore.ErrDuplicateGTIN) {
+		writeError(w, http.StatusConflict, "duplicate_gtin", "该条码(GTIN)已被其它商品使用")
+		return
+	}
+	if h.handleErr(w, err) {
+		return
+	}
+	writeJSON(w, http.StatusCreated, d)
+}
+
 // UpdateProduct applies an edit.
 func (h *Handler) UpdateProduct(w http.ResponseWriter, r *http.Request) {
 	var in adminstore.ProductInput
@@ -399,6 +427,96 @@ func (h *Handler) handleCategoryErr(w http.ResponseWriter, err error) bool {
 	return h.handleErr(w, err)
 }
 
+type brandInput struct {
+	Name string `json:"name"`
+}
+
+type brandMergeInput struct {
+	TargetID string `json:"target_id"`
+}
+
+// CreateBrand adds a brand.
+func (h *Handler) CreateBrand(w http.ResponseWriter, r *http.Request) {
+	var in brandInput
+	if err := json.NewDecoder(r.Body).Decode(&in); err != nil {
+		writeError(w, http.StatusBadRequest, "bad_request", "invalid body")
+		return
+	}
+	if strings.TrimSpace(in.Name) == "" {
+		writeError(w, http.StatusBadRequest, "bad_request", "品牌名称不能为空")
+		return
+	}
+	b, err := h.store.CreateBrand(r.Context(), auth.UserFrom(r.Context()), in.Name)
+	if h.handleBrandErr(w, err) {
+		return
+	}
+	writeJSON(w, http.StatusCreated, b)
+}
+
+// UpdateBrand renames a brand.
+func (h *Handler) UpdateBrand(w http.ResponseWriter, r *http.Request) {
+	var in brandInput
+	if err := json.NewDecoder(r.Body).Decode(&in); err != nil {
+		writeError(w, http.StatusBadRequest, "bad_request", "invalid body")
+		return
+	}
+	if strings.TrimSpace(in.Name) == "" {
+		writeError(w, http.StatusBadRequest, "bad_request", "品牌名称不能为空")
+		return
+	}
+	b, err := h.store.UpdateBrand(r.Context(), chi.URLParam(r, "id"), auth.UserFrom(r.Context()), in.Name)
+	if h.handleBrandErr(w, err) {
+		return
+	}
+	writeJSON(w, http.StatusOK, b)
+}
+
+// MergeBrands folds one brand's products into another, then deletes the source.
+func (h *Handler) MergeBrands(w http.ResponseWriter, r *http.Request) {
+	var in brandMergeInput
+	if err := json.NewDecoder(r.Body).Decode(&in); err != nil {
+		writeError(w, http.StatusBadRequest, "bad_request", "invalid body")
+		return
+	}
+	if strings.TrimSpace(in.TargetID) == "" {
+		writeError(w, http.StatusBadRequest, "bad_request", "请选择合并目标品牌")
+		return
+	}
+	b, err := h.store.MergeBrands(r.Context(), chi.URLParam(r, "id"), in.TargetID, auth.UserFrom(r.Context()))
+	if h.handleBrandErr(w, err) {
+		return
+	}
+	writeJSON(w, http.StatusOK, b)
+}
+
+// DeleteBrand removes a brand no product references.
+func (h *Handler) DeleteBrand(w http.ResponseWriter, r *http.Request) {
+	err := h.store.DeleteBrand(r.Context(), chi.URLParam(r, "id"), auth.UserFrom(r.Context()))
+	if h.handleBrandErr(w, err) {
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]string{"status": "deleted"})
+}
+
+// handleBrandErr maps brand-specific errors to client statuses.
+func (h *Handler) handleBrandErr(w http.ResponseWriter, err error) bool {
+	if err == nil {
+		return false
+	}
+	switch {
+	case errors.Is(err, adminstore.ErrDuplicateBrand):
+		writeError(w, http.StatusConflict, "duplicate_brand", "该品牌名称已存在")
+		return true
+	case errors.Is(err, adminstore.ErrBrandInUse):
+		writeError(w, http.StatusConflict, "in_use", "仍有商品使用该品牌，请先改用其它品牌或合并")
+		return true
+	case errors.Is(err, adminstore.ErrInvalidMerge):
+		writeError(w, http.StatusBadRequest, "invalid_merge", "合并目标无效（不存在或与源品牌相同）")
+		return true
+	}
+	return h.handleErr(w, err)
+}
+
 // ---------- submissions ----------
 
 // CreateSubmission accepts an anonymous public contribution into the queue.

api/internal/adminstore/brand.go

@@ -0,0 +1,154 @@
+package adminstore
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/jackc/pgx/v5"
+)
+
+// Brand-management errors, mapped to client statuses by the handler.
+var (
+	// ErrDuplicateBrand is returned when a brand name already exists.
+	ErrDuplicateBrand = errors.New("duplicate brand name")
+	// ErrBrandInUse blocks deleting a brand still referenced by products.
+	ErrBrandInUse = errors.New("brand in use")
+	// ErrInvalidMerge is returned when a merge target is missing or equal to
+	// the source.
+	ErrInvalidMerge = errors.New("invalid merge target")
+)
+
+// CreateBrand inserts a new brand. Names are unique by normalized form.
+func (s *Store) CreateBrand(ctx context.Context, actor, name string) (*Brand, error) {
+	name = strings.TrimSpace(name)
+	if name == "" {
+		return nil, errors.New("name required")
+	}
+	var b Brand
+	err := s.pool.QueryRow(ctx,
+		`INSERT INTO brand (name, normalized_name) VALUES ($1, $2) RETURNING id, name, 0`,
+		name, normBrand(name)).Scan(&b.ID, &b.Name, &b.ProductCount)
+	if isUniqueViolation(err) {
+		return nil, ErrDuplicateBrand
+	}
+	if err != nil {
+		return nil, err
+	}
+	_ = s.writeAudit(ctx, actor, "create", "brand", &b.ID, []string{"name"}, nil, b)
+	return &b, nil
+}
+
+// UpdateBrand renames a brand, keeping the normalized name in sync.
+func (s *Store) UpdateBrand(ctx context.Context, id, actor, name string) (*Brand, error) {
+	name = strings.TrimSpace(name)
+	if name == "" {
+		return nil, errors.New("name required")
+	}
+	ct, err := s.pool.Exec(ctx,
+		"UPDATE brand SET name = $1, normalized_name = $2 WHERE id = $3",
+		name, normBrand(name), id)
+	if isUniqueViolation(err) {
+		return nil, ErrDuplicateBrand
+	}
+	if err != nil {
+		return nil, err
+	}
+	if ct.RowsAffected() == 0 {
+		return nil, ErrNotFound
+	}
+	out, err := s.getBrand(ctx, id)
+	if err != nil {
+		return nil, err
+	}
+	_ = s.writeAudit(ctx, actor, "update", "brand", &id, []string{"name"}, nil, out)
+	return out, nil
+}
+
+// MergeBrands reassigns every product of src to dst, then deletes src. Useful
+// for collapsing duplicate brands (e.g. "可口可乐" and "Coca-Cola").
+func (s *Store) MergeBrands(ctx context.Context, srcID, dstID, actor string) (*Brand, error) {
+	if srcID == dstID {
+		return nil, ErrInvalidMerge
+	}
+	tx, err := s.pool.Begin(ctx)
+	if err != nil {
+		return nil, err
+	}
+	defer tx.Rollback(ctx)
+
+	var dstName string
+	err = tx.QueryRow(ctx, "SELECT name FROM brand WHERE id = $1", dstID).Scan(&dstName)
+	if errors.Is(err, pgx.ErrNoRows) {
+		return nil, ErrInvalidMerge
+	}
+	if err != nil {
+		return nil, err
+	}
+	var srcName string
+	err = tx.QueryRow(ctx, "SELECT name FROM brand WHERE id = $1", srcID).Scan(&srcName)
+	if errors.Is(err, pgx.ErrNoRows) {
+		return nil, ErrNotFound
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	if _, err := tx.Exec(ctx, "UPDATE product SET brand_id = $1 WHERE brand_id = $2", dstID, srcID); err != nil {
+		return nil, err
+	}
+	if _, err := tx.Exec(ctx, "DELETE FROM brand WHERE id = $1", srcID); err != nil {
+		return nil, err
+	}
+	if err := tx.Commit(ctx); err != nil {
+		return nil, err
+	}
+
+	out, err := s.getBrand(ctx, dstID)
+	if err != nil {
+		return nil, err
+	}
+	_ = s.writeAudit(ctx, actor, "merge", "brand", &srcID, []string{"name"},
+		map[string]string{"name": srcName},
+		map[string]string{"merged_into": dstName, "merged_into_id": dstID})
+	return out, nil
+}
+
+// DeleteBrand removes a brand not referenced by any product.
+func (s *Store) DeleteBrand(ctx context.Context, id, actor string) error {
+	before, err := s.getBrand(ctx, id)
+	if err != nil {
+		return err
+	}
+	if before.ProductCount > 0 {
+		return fmt.Errorf("%w: %d products", ErrBrandInUse, before.ProductCount)
+	}
+	ct, err := s.pool.Exec(ctx, "DELETE FROM brand WHERE id = $1", id)
+	if err != nil {
+		if isForeignKeyViolation(err) {
+			return ErrBrandInUse
+		}
+		return err
+	}
+	if ct.RowsAffected() == 0 {
+		return ErrNotFound
+	}
+	_ = s.writeAudit(ctx, actor, "delete", "brand", &id, []string{"name"}, before, nil)
+	return nil
+}
+
+func (s *Store) getBrand(ctx context.Context, id string) (*Brand, error) {
+	var b Brand
+	err := s.pool.QueryRow(ctx, `
+SELECT b.id, b.name,
+       (SELECT count(*) FROM product p WHERE p.brand_id = b.id)
+FROM brand b WHERE b.id = $1`, id).Scan(&b.ID, &b.Name, &b.ProductCount)
+	if errors.Is(err, pgx.ErrNoRows) {
+		return nil, ErrNotFound
+	}
+	if err != nil {
+		return nil, err
+	}
+	return &b, nil
+}

api/internal/adminstore/brand_test.go

@@ -0,0 +1,78 @@
+package adminstore
+
+import (
+	"context"
+	"errors"
+	"testing"
+)
+
+func TestBrandLifecycle(t *testing.T) {
+	s := newTestStore(t)
+	ctx := context.Background()
+
+	a, err := s.CreateBrand(ctx, "tester", "品牌A "+randomHex(4))
+	if err != nil {
+		t.Fatalf("create A: %v", err)
+	}
+	t.Cleanup(func() { _, _ = s.pool.Exec(ctx, "DELETE FROM brand WHERE id = $1", a.ID) })
+
+	b, err := s.CreateBrand(ctx, "tester", "品牌B "+randomHex(4))
+	if err != nil {
+		t.Fatalf("create B: %v", err)
+	}
+	t.Cleanup(func() { _, _ = s.pool.Exec(ctx, "DELETE FROM brand WHERE id = $1", b.ID) })
+
+	// Duplicate (normalized) name must be rejected.
+	if _, err := s.CreateBrand(ctx, "tester", "  "+a.Name+"  "); !errors.Is(err, ErrDuplicateBrand) {
+		t.Fatalf("expected ErrDuplicateBrand, got %v", err)
+	}
+
+	// Rename.
+	renamed, err := s.UpdateBrand(ctx, a.ID, "tester", "品牌A改名")
+	if err != nil {
+		t.Fatalf("rename: %v", err)
+	}
+	if renamed.Name != "品牌A改名" {
+		t.Fatalf("rename not applied: %q", renamed.Name)
+	}
+
+	// Attach a product to brand A so deletion is blocked and merge moves it.
+	var prodID string
+	err = s.pool.QueryRow(ctx,
+		"INSERT INTO product (name, brand_id, status) VALUES ($1,$2,'active') RETURNING id",
+		"测试商品 "+randomHex(4), a.ID).Scan(&prodID)
+	if err != nil {
+		t.Fatalf("insert product: %v", err)
+	}
+	t.Cleanup(func() { _, _ = s.pool.Exec(ctx, "DELETE FROM product WHERE id = $1", prodID) })
+
+	// Deleting an in-use brand must fail.
+	if err := s.DeleteBrand(ctx, a.ID, "tester"); !errors.Is(err, ErrBrandInUse) {
+		t.Fatalf("expected ErrBrandInUse, got %v", err)
+	}
+
+	// Merge A into B: product reassigned, A deleted.
+	merged, err := s.MergeBrands(ctx, a.ID, b.ID, "tester")
+	if err != nil {
+		t.Fatalf("merge: %v", err)
+	}
+	if merged.ID != b.ID || merged.ProductCount < 1 {
+		t.Fatalf("merge result wrong: %+v", merged)
+	}
+	if _, err := s.getBrand(ctx, a.ID); !errors.Is(err, ErrNotFound) {
+		t.Fatalf("source brand should be gone, got %v", err)
+	}
+
+	// Self-merge is invalid.
+	if _, err := s.MergeBrands(ctx, b.ID, b.ID, "tester"); !errors.Is(err, ErrInvalidMerge) {
+		t.Fatalf("expected ErrInvalidMerge, got %v", err)
+	}
+
+	// After moving the product away from B, B can be deleted.
+	if _, err := s.pool.Exec(ctx, "DELETE FROM product WHERE id = $1", prodID); err != nil {
+		t.Fatalf("cleanup product: %v", err)
+	}
+	if err := s.DeleteBrand(ctx, b.ID, "tester"); err != nil {
+		t.Fatalf("delete unused brand: %v", err)
+	}
+}

api/internal/adminstore/write.go

@@ -170,6 +170,79 @@ ON CONFLICT (product_id) DO UPDATE SET
 	return after, nil
 }
 
+// ErrDuplicateGTIN is returned when a product GTIN already exists.
+var ErrDuplicateGTIN = errors.New("duplicate gtin")
+
+// CreateProduct inserts a new product from the admin UI. Only the core fields
+// are required; the operator completes the rest in the detail editor.
+func (s *Store) CreateProduct(ctx context.Context, actor string, in ProductInput) (*ProductDetail, error) {
+	if strings.TrimSpace(in.Name) == "" {
+		return nil, errors.New("name required")
+	}
+	tx, err := s.pool.Begin(ctx)
+	if err != nil {
+		return nil, err
+	}
+	defer tx.Rollback(ctx)
+
+	brandID := in.BrandID
+	if in.BrandName != nil && strings.TrimSpace(*in.BrandName) != "" {
+		bid, err := s.ensureBrand(ctx, tx, strings.TrimSpace(*in.BrandName))
+		if err != nil {
+			return nil, err
+		}
+		brandID = &bid
+	}
+
+	var gpc *string
+	if in.CategoryID != nil && *in.CategoryID != "" {
+		if err := tx.QueryRow(ctx, "SELECT gpc_brick_code FROM category WHERE id = $1", *in.CategoryID).Scan(&gpc); err != nil && !errors.Is(err, pgx.ErrNoRows) {
+			return nil, err
+		}
+	}
+
+	canonical, err := s.netCanonical(ctx, tx, in.NetContentValue, in.NetContentUnit)
+	if err != nil {
+		return nil, err
+	}
+
+	status := in.Status
+	if status == "" {
+		status = "active"
+	}
+
+	var id string
+	err = tx.QueryRow(ctx, `
+INSERT INTO product (gtin, name, brand_id, category_id, gpc_brick_code,
+   net_content_value, net_content_unit, net_content_canonical,
+   country_of_origin, status)
+VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10)
+RETURNING id`,
+		in.GTIN, in.Name, brandID, in.CategoryID, gpc,
+		in.NetContentValue, in.NetContentUnit, canonical,
+		in.CountryOfOrigin, status).Scan(&id)
+	if isUniqueViolation(err) {
+		return nil, ErrDuplicateGTIN
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	if _, err := s.recomputeQualityTx(ctx, tx, id); err != nil {
+		return nil, err
+	}
+	if err := tx.Commit(ctx); err != nil {
+		return nil, err
+	}
+
+	after, err := s.GetProduct(ctx, id)
+	if err != nil {
+		return nil, err
+	}
+	_ = s.writeAudit(ctx, actor, "create", "product", &id, []string{"name"}, nil, after)
+	return after, nil
+}
+
 func strEq(a, b *string) bool {
 	if a == nil && b == nil {
 		return true
@@ -330,15 +403,21 @@ func (s *Store) DeleteMSRP(ctx context.Context, productID, msrpID, actor string)
 
 // ---------- dictionaries ----------
 
-// Brand is a brand option for the edit form.
+// Brand is a brand option for the edit form and the management view.
 type Brand struct {
-	ID   string `json:"id"`
-	Name string `json:"name"`
+	ID           string `json:"id"`
+	Name         string `json:"name"`
+	ProductCount int    `json:"product_count"`
 }
 
-// ListBrands returns all brands ordered by name.
+// ListBrands returns all brands ordered by name, with the number of products
+// referencing each one.
 func (s *Store) ListBrands(ctx context.Context) ([]Brand, error) {
-	rows, err := s.pool.Query(ctx, "SELECT id, name FROM brand ORDER BY name")
+	rows, err := s.pool.Query(ctx, `
+SELECT b.id, b.name,
+       (SELECT count(*) FROM product p WHERE p.brand_id = b.id) AS product_count
+FROM brand b
+ORDER BY b.name`)
 	if err != nil {
 		return nil, err
 	}
@@ -346,7 +425,7 @@ func (s *Store) ListBrands(ctx context.Context) ([]Brand, error) {
 	out := []Brand{}
 	for rows.Next() {
 		var b Brand
-		if err := rows.Scan(&b.ID, &b.Name); err != nil {
+		if err := rows.Scan(&b.ID, &b.Name, &b.ProductCount); err != nil {
 			return nil, err
 		}
 		out = append(out, b)