feat(backend): 出入库搜索重构 + 商品编码搜索 + KPI/确认售价/详细搜索

- 搜索 keyword 命中改为 单号/酒名(名+拼音)/商品编码，去掉往来单位匹配
- applyStockOrderDetailFilters 合并明细过滤为单条子查询（同一明细语义）+ 新增 product_code
- 新增出入库 KPI summary、出库确认售价(confirm-sale) 及路由
- 补充/更新对应单元测试

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/internal/handler/stock_in_test.go

@@ -101,6 +101,94 @@ func TestStockInHandler_List(t *testing.T) {
 	assert.Equal(t, float64(2), resp["total"].(float64))
 }
 
+func TestStockInHandler_Summary(t *testing.T) {
+	db := testutil.SetupTestDB()
+	shop := testutil.CreateTestShop(db, "SISUM")
+	user := testutil.CreateTestUser(db, shop.ID, "admin", "pass", "admin")
+	wh := testutil.CreateTestWarehouse(db, shop.ID, "W")
+	token := getAuthToken(user.ID, shop.ID, "admin")
+	r := setupProtectedRouter(db)
+
+	for i := 0; i < 2; i++ {
+		makeRequest(r, "POST", "/api/v1/stock-in/orders", token, map[string]interface{}{
+			"warehouse_id": wh.ID,
+			"order_date":   time.Now().Format(time.RFC3339),
+			"items":        []map[string]interface{}{{"product_name": "A", "quantity": 2.0, "unit_price": 100.0}},
+		})
+	}
+	var first model.StockInOrder
+	db.Where("shop_id = ?", shop.ID).Order("id ASC").First(&first)
+	makeRequest(r, "PUT", fmt.Sprintf("/api/v1/stock-in/orders/%d/submit", first.ID), token, nil)
+
+	w := makeRequest(r, "GET", "/api/v1/stock-in/summary", token, nil)
+	require.Equal(t, http.StatusOK, w.Code)
+	s := parseResponse(w)
+	assert.Equal(t, float64(2), s["month_count"])
+	assert.Equal(t, float64(400), s["month_amount"])
+	assert.Equal(t, float64(1), s["pending_count"])
+}
+
+func TestStockInHandler_DetailFilter(t *testing.T) {
+	db := testutil.SetupTestDB()
+	shop := testutil.CreateTestShop(db, "SIDF")
+	user := testutil.CreateTestUser(db, shop.ID, "admin", "pass", "admin")
+	wh := testutil.CreateTestWarehouse(db, shop.ID, "W")
+	token := getAuthToken(user.ID, shop.ID, "admin")
+	r := setupProtectedRouter(db)
+
+	makeRequest(r, "POST", "/api/v1/stock-in/orders", token, map[string]interface{}{
+		"warehouse_id": wh.ID, "order_date": time.Now().Format(time.RFC3339),
+		"items": []map[string]interface{}{{"product_name": "BlueWine", "series": "Blue", "spec": "500ml", "quantity": 1.0, "unit_price": 10.0}},
+	})
+	makeRequest(r, "POST", "/api/v1/stock-in/orders", token, map[string]interface{}{
+		"warehouse_id": wh.ID, "order_date": time.Now().Format(time.RFC3339),
+		"items": []map[string]interface{}{{"product_name": "PlainWine", "series": "Plain", "spec": "480ml", "quantity": 1.0, "unit_price": 10.0}},
+	})
+
+	// 系列过滤（JOIN 明细）
+	w := makeRequest(r, "GET", "/api/v1/stock-in/orders?series=Blue", token, nil)
+	require.Equal(t, http.StatusOK, w.Code)
+	assert.Equal(t, float64(1), parseResponse(w)["total"])
+	// 商品信息过滤（明细快照名 LIKE）
+	w = makeRequest(r, "GET", "/api/v1/stock-in/orders?product=Plain", token, nil)
+	assert.Equal(t, float64(1), parseResponse(w)["total"])
+	// 规格过滤
+	w = makeRequest(r, "GET", "/api/v1/stock-in/orders?spec=500ml", token, nil)
+	assert.Equal(t, float64(1), parseResponse(w)["total"])
+	// 组合：系列 Blue + 规格 480ml → 无交集
+	w = makeRequest(r, "GET", "/api/v1/stock-in/orders?series=Blue&spec=480ml", token, nil)
+	assert.Equal(t, float64(0), parseResponse(w)["total"])
+
+	// 商品编码过滤（明细 product_code LIKE）：给 BlueWine 明细设已知码再按子串筛
+	db.Model(&model.StockInItem{}).
+		Where("shop_id = ? AND product_name = ?", shop.ID, "BlueWine").
+		Update("product_code", "PC-XYZ")
+	w = makeRequest(r, "GET", "/api/v1/stock-in/orders?product_code=XYZ", token, nil)
+	assert.Equal(t, float64(1), parseResponse(w)["total"])
+
+	// 同一明细语义：一张单两条明细，系列在明细1、规格分属明细2。
+	makeRequest(r, "POST", "/api/v1/stock-in/orders", token, map[string]interface{}{
+		"warehouse_id": wh.ID, "order_date": time.Now().Format(time.RFC3339),
+		"items": []map[string]interface{}{
+			{"product_name": "MixA", "series": "MixS", "spec": "111", "quantity": 1.0, "unit_price": 10.0},
+			{"product_name": "MixB", "series": "OtherS", "spec": "222", "quantity": 1.0, "unit_price": 10.0},
+		},
+	})
+	// 跨明细组合（系列在明细1、规格在明细2）→ 同一明细语义下无单命中
+	w = makeRequest(r, "GET", "/api/v1/stock-in/orders?series=MixS&spec=222", token, nil)
+	assert.Equal(t, float64(0), parseResponse(w)["total"])
+	// 同一明细命中（系列 MixS + 规格 111 均在明细1）→ 1
+	w = makeRequest(r, "GET", "/api/v1/stock-in/orders?series=MixS&spec=111", token, nil)
+	assert.Equal(t, float64(1), parseResponse(w)["total"])
+
+	// 退单状态过滤：把一单标 partial 再按 return_state 筛
+	var one model.StockInOrder
+	db.Where("shop_id = ?", shop.ID).First(&one)
+	db.Model(&model.StockInOrder{}).Where("id = ?", one.ID).Update("return_state", "partial")
+	w = makeRequest(r, "GET", "/api/v1/stock-in/orders?return_state=partial", token, nil)
+	assert.Equal(t, float64(1), parseResponse(w)["total"])
+}
+
 func TestStockInHandler_Submit_WrongStatus(t *testing.T) {
 	db := testutil.SetupTestDB()
 	shop := testutil.CreateTestShop(db, "SI003")
@@ -438,9 +526,10 @@ func TestStockInHandler_List_FilterByKeyword(t *testing.T) {
 	})
 	require.Equal(t, http.StatusCreated, w.Code)
 
-	// 按往来单位名搜索 → 只命中单据1
+	// 往来单位名不再进入 keyword 范围（供应商/客户改由工具栏下拉筛选）→ 搜不到
+	// （商品是 Brandy，不含「茅台」）
 	w = makeRequest(r, "GET", "/api/v1/stock-in/orders?keyword=茅台", token, nil)
-	assert.Equal(t, float64(1), parseResponse(w)["total"].(float64))
+	assert.Equal(t, float64(0), parseResponse(w)["total"].(float64))
 
 	// 按单号搜索 → 只命中单据1
 	w = makeRequest(r, "GET", "/api/v1/stock-in/orders?keyword="+order1No, token, nil)