docs(plan): INT-3 migration table wording

Co-Authored-By: Claude Opus 5.5 <[email protected]>

docs/plan/08-v0.2-closeout.md

@@ -136,7 +136,7 @@ BR-3 已先行合并(`80f0fa0`)。本轮把六个 worktree 分支依次 `git mer
 
 | 迁移 | 来源 | 内容 |
 | --- | --- | --- |
-| `0050_storage_retention` | CACHE-2 | 存储预算 / 保留相关表与索引 |
+| `0050_storage_retention` | CACHE-2 | 流水表按时间清理的索引 + 按表 autovacuum 参数 |
 | `0051_tmdb_cache_size` | INT-3 `fe05138` | 已存设置里 `cache.tmdbMaxSize` 仍是旧缺省 256 的改成 5000(用户库当前是 256) |
 | `0052_agent_run_created_by` | INT-3 `e681fce` | `agent_run (created_by, created_at desc)` 索引,供巡检汇总 |