getVideoAggList：hot 池时间衰减 α 由 0.8 改为 0.5，加强新视频权重、压制老视频刷天数。

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

api-module/src/main/resources/mapper/contentplatform/ext/ContentPlatformPlanMapperExt.xml

@@ -264,7 +264,7 @@
         FROM (
         SELECT video_id, category, title, cover, video,
             SUM(IFNULL(rovn, 0) * (1 + LN(GREATEST(IFNULL(exposure, 0) / 5000.0, 1.0)))
-                * POWER(0.8, DATEDIFF(STR_TO_DATE(#{aggDt}, '%Y%m%d'), STR_TO_DATE(dt, '%Y%m%d'))))
+                * POWER(0.5, DATEDIFF(STR_TO_DATE(#{aggDt}, '%Y%m%d'), STR_TO_DATE(dt, '%Y%m%d'))))
                 OVER (PARTITION BY video_id) AS weighted_score,
             ROW_NUMBER() OVER (PARTITION BY video_id ORDER BY dt DESC) AS rn
         FROM content_platform_video