feat(backend): 出入库编码搜索双路匹配+建单填快照；finance 趋势/日期区间；partner/product 拼音搜索

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JJ1g8XV1YhhmHRzhwWEW7o

backend/internal/handler/stock_in.go

@@ -57,14 +57,15 @@ func (h *StockInHandler) List(c *gin.Context) {
 		// 酒名「product 主数据名 OR 明细快照名」任一命中——不能用 COALESCE 二选一：历史导入单的
 		// 明细 product_id 统一指向占位商品「历史导入占位」（p.name 非空），COALESCE 会被占位名劫持，
 		// 永远取不到真实快照 product_name，导致导入单按真实酒名搜不到。拼音只在 products 上（快照无拼音列）。
+		// 编码同理「主数据 p.code OR 快照 it.product_code」双匹配，与页面显示口径（主数据优先）对齐。
 		query = query.Where(
 			"order_no LIKE ?"+
 				" OR id IN (SELECT it.order_id FROM stock_in_items it"+
 				"   LEFT JOIN products p ON p.id = it.product_id AND p.shop_id = it.shop_id"+
 				"   WHERE it.shop_id = ? AND it.deleted_at IS NULL"+
 				"     AND (p.name LIKE ? OR it.product_name LIKE ? OR it.product_code LIKE ?"+
-				"          OR p.name_pinyin LIKE ? OR p.name_initials LIKE ?))",
-			like, shopID, like, like, like, like, like,
+				"          OR p.code LIKE ? OR p.name_pinyin LIKE ? OR p.name_initials LIKE ?))",
+			like, shopID, like, like, like, like, like, like,
 		)
 	}
 	// 详细搜索多字段（各参数独立可选、组合为 AND）
@@ -109,12 +110,14 @@ func applyStockOrderDetailFilters(q *gorm.DB, shopID uint64, c *gin.Context, ite
 		like := "%" + v + "%"
 		itemConds = append(itemConds,
 			"(p.name LIKE ? OR it.product_name LIKE ? OR it.product_code LIKE ?"+
-				" OR p.name_pinyin LIKE ? OR p.name_initials LIKE ?)")
-		itemArgs = append(itemArgs, like, like, like, like, like)
+				" OR p.code LIKE ? OR p.name_pinyin LIKE ? OR p.name_initials LIKE ?)")
+		itemArgs = append(itemArgs, like, like, like, like, like, like)
 	}
+	// 编码「主数据 OR 快照」双匹配：存量出库明细快照有空串，只查快照会漏单
 	if v := strings.TrimSpace(c.Query("product_code")); v != "" {
-		itemConds = append(itemConds, "it.product_code LIKE ?")
-		itemArgs = append(itemArgs, "%"+v+"%")
+		like := "%" + v + "%"
+		itemConds = append(itemConds, "(it.product_code LIKE ? OR p.code LIKE ?)")
+		itemArgs = append(itemArgs, like, like)
 	}
 	if v := strings.TrimSpace(c.Query("series")); v != "" {
 		itemConds = append(itemConds, "it.series = ?")