feat(tools): import 90-day fan history from public data source

tools/seed_preview_db.py

@@ -389,6 +389,12 @@ def _seed_up_stats(
 
     inserted = 0
     for mid, data in latest.items():
+        existing = conn.execute(
+            "SELECT COUNT(*) FROM up_stat WHERE mid = ? AND ok = 1", (int(mid),)
+        ).fetchone()[0]
+        if int(existing) >= 2:
+            # 已有真实历史时保留原样，不合成粉丝数据。
+            continue
         follower = int(data.get("follower") or 0)
         following = data.get("following")
         current = follower