feat: EOD 23:15 seal + midnight seed shell for video/fans

Move daily snapshot/fans to 23:15 and add 00:01 seed that clones
last_completed ok=1 rows into today without advancing completed.
Evening runs force through seed markers; growth previous is per-aid
adjacent. Home shows short-update clock + 全站数据 date, and 收录视频
counts.

reaction_board/services/snapshot.py

@@ -5,6 +5,8 @@
 
 * 对 ``active`` / ``unfaved`` 视频逐条请求 ``view``；
 * 成功写入七项指标；``ok=1`` 的同日快照直接跳过（断点续跑；含小时任务 1 小时内刚刷新的）；
+* 午夜 ``seed_at`` 用上一完成日 ok=1 行克隆出当日壳（``snapshot:seeded`` / ``fans:seeded``），不推进完成日；
+* 晚间 ``snapshot_at`` 全量必须 force 打穿 seed，成功后才写完成日并清除 seeded；
 * ``run_recent_videos`` 只刷新近 N 天新片的当日行，不改完成日 / 备份；
 * 视频不可访问时标记 ``removed``；
 * 其他错误最多重试 3 次，仍失败写 ``ok=0`` 占位，不写假零值；
@@ -129,18 +131,43 @@ class SnapshotService:
     def backup_error_key(stat_date: str) -> str:
         return f"snapshot:backup_error:{stat_date}"
 
+    @staticmethod
+    def seeded_key(stat_date: str) -> str:
+        return f"snapshot:seeded:{stat_date}"
+
+    @staticmethod
+    def fans_seeded_key(stat_date: str) -> str:
+        return f"fans:seeded:{stat_date}"
+
     def run_if_needed(
         self, *, date: str | None = None, force: bool = False
     ) -> SnapshotSummary:
-        """视频快照（含 UP 头像补齐）；粉丝采集请用 ``run_fans_if_needed``。"""
+        """视频快照（含 UP 头像补齐）；粉丝采集请用 ``run_fans_if_needed``。
+
+        当日若仅有午夜 seed 壳且未 ``force``，直接返回等待晚间落盘，
+        避免把「全员 skip」误标成 completed。
+        """
         now = self._now()
         stat_date = date or shanghai_date(now)
         if not is_date(stat_date):
             raise ValueError(f"日期格式必须是 YYYY-MM-DD: {stat_date!r}")
+        seeded = self.repo.kv_get(self.seeded_key(stat_date)) == "1"
         if force:
             return self.run_videos(date=stat_date, force=True)
 
         completed = self.repo.kv_get(self.completed_key(stat_date)) == "1"
+        if seeded and not completed:
+            self._log(
+                "info", "snapshot.skip",
+                stat_date=stat_date, reason="seeded_pending_seal",
+            )
+            return SnapshotSummary(
+                stat_date=stat_date,
+                started_at=now,
+                finished_at=now,
+                completed=False,
+                already_completed=False,
+            )
         pending = self.repo.pending_snapshot_aids(stat_date)
         if completed and not pending:
             if self.repo.kv_get(self.backup_key(stat_date)) != "1":
@@ -256,6 +283,8 @@ class SnapshotService:
         self.repo.kv_set("snapshot:last_attempt", stat_date)
         if summary.completed:
             self.repo.kv_set("snapshot:last_completed", stat_date)
+            # 真落盘后清掉午夜 seed 标记。
+            self.repo.kv_delete(self.seeded_key(stat_date))
         elif self.repo.kv_get("snapshot:last_completed") == stat_date:
             self.repo.kv_set("snapshot:last_completed", "")
 
@@ -378,7 +407,24 @@ class SnapshotService:
             )
             self._log("info", "fans.skip", stat_date=stat_date, reason="no_track_fans")
             return summary
-        if not force and not self._pending_fan_mids(stat_date, cfg.track_fans):
+        seeded = self.repo.kv_get(self.fans_seeded_key(stat_date)) == "1"
+        if force or seeded:
+            # 晚间/显式 force，或存在 seed 壳时必须重采（seeded 时由调度传入 force）。
+            if seeded and not force:
+                self._log(
+                    "info", "fans.skip",
+                    stat_date=stat_date, reason="seeded_pending_seal",
+                )
+                return SnapshotSummary(
+                    stat_date=stat_date,
+                    started_at=now,
+                    finished_at=now,
+                    completed=False,
+                    already_completed=False,
+                    fans_skipped=len(cfg.track_fans),
+                )
+            return self.run_fans(date=stat_date, force=True)
+        if not self._pending_fan_mids(stat_date, cfg.track_fans):
             self._log("info", "fans.skip", stat_date=stat_date, reason="already_completed")
             return SnapshotSummary(
                 stat_date=stat_date,
@@ -456,6 +502,11 @@ class SnapshotService:
         # 独立粉丝任务用 completed 表示粉丝段成败；合并进视频摘要时不改动视频完成标记。
         if standalone:
             summary.completed = fans_ok
+            if fans_ok:
+                self.repo.kv_delete(self.fans_seeded_key(stat_date))
+        elif fans_ok:
+            # CLI 合并跑：粉丝段成功也清 seed。
+            self.repo.kv_delete(self.fans_seeded_key(stat_date))
         summary.finished_at = self._now()
         self._log(
             "info" if fans_ok else "warning",
@@ -468,6 +519,76 @@ class SnapshotService:
         )
         return summary
 
+
+    def run_seed_from_last_completed(
+        self, *, date: str | None = None
+    ) -> SnapshotSummary:
+        """用上一完成日的 ok=1 行克隆出当日壳（视频 + 粉丝）。
+
+        不写 ``snapshot:completed`` / ``snapshot:last_completed``；
+        仅打 ``snapshot:seeded`` / ``fans:seeded``，供白天展示与晚间 force 重采。
+        """
+        cfg = self.config_store.get()
+        now = self._now()
+        stat_date = date or shanghai_date(now)
+        if not is_date(stat_date):
+            raise ValueError(f"日期格式必须是 YYYY-MM-DD: {stat_date!r}")
+
+        summary = SnapshotSummary(stat_date=stat_date, started_at=now)
+        source = self.repo.kv_get("snapshot:last_completed")
+        if not source or source >= stat_date:
+            self._log(
+                "info", "snapshot.seed_skip",
+                stat_date=stat_date, reason="no_source", source=source,
+            )
+            summary.finished_at = self._now()
+            summary.completed = True
+            return summary
+        if self.repo.kv_get(self.completed_key(stat_date)) == "1":
+            self._log(
+                "info", "snapshot.seed_skip",
+                stat_date=stat_date, reason="already_completed",
+            )
+            summary.finished_at = self._now()
+            summary.completed = True
+            summary.already_completed = True
+            return summary
+        if self.repo.kv_get(self.seeded_key(stat_date)) == "1":
+            self._log(
+                "info", "snapshot.seed_skip",
+                stat_date=stat_date, reason="already_seeded", source=source,
+            )
+            summary.finished_at = self._now()
+            summary.completed = True
+            summary.already_completed = True
+            return summary
+
+        copied = self.repo.copy_ok_snapshots(
+            source, stat_date, captured_at=now, src="seed",
+        )
+        fans_copied = 0
+        if cfg.track_fans:
+            fans_copied = self.repo.copy_ok_up_stats(
+                source, stat_date, captured_at=now, mids=cfg.track_fans,
+            )
+            self.repo.kv_set(self.fans_seeded_key(stat_date), "1")
+        self.repo.kv_set(self.seeded_key(stat_date), "1")
+        summary.total = copied
+        summary.success = copied
+        summary.fans_ok = fans_copied
+        if copied or fans_copied:
+            self.repo.bump_cache_version("videos")
+            if fans_copied:
+                self.repo.bump_cache_version("fans")
+        summary.finished_at = self._now()
+        summary.completed = True  # seed 任务本身成功；不等于快照落盘完成
+        self._log(
+            "info", "snapshot.seed_done",
+            stat_date=stat_date, source=source,
+            copied=copied, fans_copied=fans_copied,
+        )
+        return summary
+
     def _pending_fan_mids(self, stat_date: str, mids: tuple[int, ...] | list[int]) -> list[int]:
         pending: list[int] = []
         for mid in mids: