feat: home growth auto(7→1) and hourly recent-video snapshot

- Add analytics.home_growth_days (auto|1|7); API growth_days=auto tries 7 then 1
- Homepage shows active window and growth-board link; clearer empty reason
- New snapshot_recent scheduler task (schedule.recent_snapshot_minutes/days)
- run_recent_videos refreshes new aids only; never touches completed/backup
- Full 00:01 job keeps ok=1 skip (covers hourly refresh within 1h); mutex with recent

reaction_board/cli.py

@@ -163,6 +163,13 @@ def _clear_task_running(repo: Repository, name: str) -> None:
         pass
 
 
+def _is_task_running(repo: Repository, name: str) -> bool:
+    try:
+        return bool(repo.kv_get(_task_running_key(name)))
+    except Exception:  # noqa: BLE001
+        return False
+
+
 def _record_task(
     repo: Repository,
     name: str,
@@ -547,6 +554,16 @@ def cmd_run(args, logger: JsonLogger, *, serve_web: bool = False) -> int:
 
         def run_snapshot():
             started = int(time.time())
+            if _is_task_running(repo, "snapshot_recent"):
+                logger.info(
+                    "snapshot.skip", reason="snapshot_recent_running",
+                )
+                _record_task(
+                    repo, "snapshot", ok=True, started_at=started,
+                    finished_at=int(time.time()),
+                    payload={"skipped": True, "reason": "snapshot_recent_running"},
+                )
+                return None
             _mark_task_running(repo, "snapshot", started_at=started)
             try:
                 summary = snapshot_service.run_if_needed()
@@ -567,6 +584,39 @@ def cmd_run(args, logger: JsonLogger, *, serve_web: bool = False) -> int:
             logger.info("snapshot.summary", **payload)
             return summary
 
+        def run_snapshot_recent():
+            started = int(time.time())
+            if _is_task_running(repo, "snapshot"):
+                logger.info(
+                    "snapshot.recent_skip", reason="snapshot_running",
+                )
+                _record_task(
+                    repo, "snapshot_recent", ok=True, started_at=started,
+                    finished_at=int(time.time()),
+                    payload={"skipped": True, "reason": "snapshot_running"},
+                )
+                return None
+            _mark_task_running(repo, "snapshot_recent", started_at=started)
+            try:
+                summary = snapshot_service.run_recent_videos()
+            except Exception as exc:  # noqa: BLE001
+                _record_task(
+                    repo, "snapshot_recent", ok=False, started_at=started,
+                    finished_at=int(time.time()), error=str(exc),
+                )
+                raise
+            payload = summary.as_dict()
+            ok = summary.failed == 0
+            error = "；".join(summary.errors) if summary.errors else None
+            _record_task(
+                repo, "snapshot_recent", ok=ok, started_at=summary.started_at,
+                finished_at=summary.finished_at or int(time.time()),
+                payload=payload, error=error,
+            )
+            last["snapshot_recent"] = summary
+            logger.info("snapshot.recent_summary", **payload)
+            return summary
+
         def run_fans():
             started = int(time.time())
             _mark_task_running(repo, "fans", started_at=started)
@@ -601,6 +651,7 @@ 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}"
+        recent_minutes = int(store.get().schedule.recent_snapshot_minutes)
         scheduler = Scheduler(
             [
                 ScheduledTask(
@@ -617,6 +668,11 @@ def cmd_run(args, logger: JsonLogger, *, serve_web: bool = False) -> int:
                     next_run=0.0,
                     next_run_fn=lambda started: next_daily_run(started, snapshot_at),
                 ),
+                ScheduledTask(
+                    "snapshot_recent",
+                    float(recent_minutes * 60),
+                    run_snapshot_recent,
+                ),
                 ScheduledTask(
                     "discovery",
                     float(cfg.schedule.discover_minutes * 60),