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/cli.py

@@ -566,7 +566,12 @@ def cmd_run(args, logger: JsonLogger, *, serve_web: bool = False) -> int:
                 return None
             _mark_task_running(repo, "snapshot", started_at=started)
             try:
-                summary = snapshot_service.run_if_needed()
+                # 晚间全量：若当日是午夜 seed 壳，必须 force 打穿 ok=1 克隆行。
+                today = shanghai_date()
+                force_seed = repo.kv_get(
+                    SnapshotService.seeded_key(today)
+                ) == "1"
+                summary = snapshot_service.run_if_needed(force=force_seed)
             except Exception as exc:  # noqa: BLE001
                 _record_task(
                     repo, "snapshot", ok=False, started_at=started,
@@ -621,7 +626,11 @@ def cmd_run(args, logger: JsonLogger, *, serve_web: bool = False) -> int:
             started = int(time.time())
             _mark_task_running(repo, "fans", started_at=started)
             try:
-                summary = snapshot_service.run_fans_if_needed()
+                today = shanghai_date()
+                force_seed = repo.kv_get(
+                    SnapshotService.fans_seeded_key(today)
+                ) == "1"
+                summary = snapshot_service.run_fans_if_needed(force=force_seed)
             except Exception as exc:  # noqa: BLE001
                 _record_task(
                     repo, "fans", ok=False, started_at=started,
@@ -642,6 +651,27 @@ def cmd_run(args, logger: JsonLogger, *, serve_web: bool = False) -> int:
             logger.info("fans.summary", **payload)
             return summary
 
+        def run_snapshot_seed():
+            started = int(time.time())
+            _mark_task_running(repo, "snapshot_seed", started_at=started)
+            try:
+                summary = snapshot_service.run_seed_from_last_completed()
+            except Exception as exc:  # noqa: BLE001
+                _record_task(
+                    repo, "snapshot_seed", ok=False, started_at=started,
+                    finished_at=int(time.time()), error=str(exc),
+                )
+                raise
+            payload = summary.as_dict()
+            _record_task(
+                repo, "snapshot_seed", ok=True, started_at=summary.started_at,
+                finished_at=summary.finished_at or int(time.time()),
+                payload=payload,
+            )
+            last["snapshot_seed"] = summary
+            logger.info("snapshot.seed_summary", **payload)
+            return summary
+
         def run_config_watch():
             before = store.revision
             store.get()
@@ -651,9 +681,18 @@ def cmd_run(args, logger: JsonLogger, *, serve_web: bool = False) -> int:
 
         hh, mm = parse_hhmm(cfg.schedule.snapshot_at)
         snapshot_at = f"{hh:02d}:{mm:02d}"
+        sh, sm = parse_hhmm(cfg.schedule.seed_at)
+        seed_at = f"{sh:02d}:{sm:02d}"
         recent_minutes = int(store.get().schedule.recent_snapshot_minutes)
         scheduler = Scheduler(
             [
+                ScheduledTask(
+                    "snapshot_seed",
+                    86400.0,
+                    run_snapshot_seed,
+                    next_run=0.0,
+                    next_run_fn=lambda started: next_daily_run(started, seed_at),
+                ),
                 ScheduledTask(
                     "snapshot",
                     86400.0,
@@ -707,6 +746,7 @@ def cmd_run(args, logger: JsonLogger, *, serve_web: bool = False) -> int:
             logger.info(
                 "scheduler.start",
                 snapshot_at=snapshot_at,
+                seed_at=seed_at,
             )
             scheduler.run_forever()