docs(mp): banner changelog 修正 seasons 为小写字典值 (spring/summer/autumn/winter)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

changelogs/2026-04/2026-04-19_mp-banner-active-link-target.md

@@ -42,7 +42,7 @@ Banner 列表每个元素在原有字段基础上新增：
     "subtitle": null,
     "coverImageUrl": "https://cdn.example.com/line-cover.jpg",
     "productType": "GROUP",
-    "seasons": ["SPRING", "SUMMER"],
+    "seasons": ["spring", "summer"],
     "lineId": null
   }
 }
@@ -58,7 +58,7 @@ Banner 列表每个元素在原有字段基础上新增：
 | `subtitle` | string \| null | 副标题 | null | ✅ |
 | `coverImageUrl` | string \| null | 封面图 URL | ✅ | ✅ |
 | `productType` | string | `CORE` / `GROUP` / `CUSTOM` | ✅ | ✅ |
-| `seasons` | string[] | 适用季节，字典 `season`：`SPRING` / `SUMMER` / `AUTUMN` / `WINTER` | ✅ | ✅ |
+| `seasons` | string[] | 适用季节，字典 `product_season`：`spring` / `summer` / `autumn` / `winter`（**小写**） | ✅ | ✅ |
 | `lineId` | long \| null | 所属产品线 ID | null | ✅ |
 
 ### `linkTarget=null` 的情况
@@ -97,10 +97,10 @@ banners.forEach(banner => {
 
 ```js
 const SEASON_LABEL = {
-  SPRING: '春季',
-  SUMMER: '夏季',
-  AUTUMN: '秋季',
-  WINTER: '冬季',
+  spring: '春季',
+  summer: '夏季',
+  autumn: '秋季',
+  winter: '冬季',
 };
 // target.seasons.map(s => SEASON_LABEL[s]) → ['春季', '夏季']
 ```