feat(snapshot): refresh API video metadata; keep removed visible

入库 / 小时近新片 / 全量快照成功时以 view_detail 覆盖 title、duration、
pages、cover、bvid、up_*、pubdate 等接口字段，并照旧写七项快照。
原站失效仅标 removed，不删行、不空写元数据；列表与详情继续展示，
快照队列仍跳过 removed。

reaction_board/services/library.py

@@ -116,11 +116,37 @@ class LibraryService:
         if candidate is None:
             video = self.repo.get_video(aid)
             if video is not None:
+                # 已在库：仍以接口为准刷新元数据（不重复建档）
+                try:
+                    detail = self.read_provider.get().view_detail(aid=aid)
+                except BilibiliError as exc:
+                    self._log("warning", "ingest.detail_failed", aid=aid, error=str(exc))
+                    return IngestResult(
+                        ok=True, aid=aid, state="exists",
+                        title=str(video.get("title") or ""),
+                        up_name=str(video.get("up_name") or ""),
+                        message="已在库，无需重复入库",
+                    )
+                self.repo.refresh_video_metadata(
+                    aid=detail.aid,
+                    bvid=detail.bvid,
+                    title=detail.title,
+                    up_mid=detail.up_mid,
+                    up_name=detail.up_name,
+                    pubdate=detail.pubdate,
+                    duration=detail.duration,
+                    pages=detail.pages,
+                    cover=detail.cover,
+                    up_face=detail.up_face,
+                    now=self._now(),
+                )
+                self._write_snapshot(detail)
+                self.repo.bump_cache_version("videos")
                 return IngestResult(
                     ok=True, aid=aid, state="exists",
-                    title=str(video.get("title") or ""),
-                    up_name=str(video.get("up_name") or ""),
-                    message="已在库，无需重复入库",
+                    title=detail.title,
+                    up_name=detail.up_name or "",
+                    message="已在库，已刷新元数据",
                 )
             return IngestResult(
                 ok=False, aid=aid, state="missing", message="候选不存在或已处理"