fix(web): align trend ranges, next runs and preview task records

tools/seed_preview_db.py

@@ -254,6 +254,69 @@ def _insert_snapshot(
     )
 
 
+def _seed_task_records(conn: sqlite3.Connection, latest_day: date) -> None:
+    """写入可读的最近任务状态，让预览系统页有内容可看。"""
+    base = _timestamp(latest_day, hour=0, minute=1)
+    records = {
+        "snapshot": {
+            "name": "snapshot", "ok": True,
+            "started_at": int(base),
+            "finished_at": int(base + 1124),
+            "error": None,
+            "summary": {
+                "stat_date": latest_day.isoformat(), "total": 796, "ok": 796,
+                "failed": 0, "removed": 0, "completed": True,
+                "backup_path": f"data/backup/app-{latest_day.strftime('%Y%m%d')}.db",
+            },
+        },
+        "folder_sync": {
+            "name": "folder_sync", "ok": True,
+            "started_at": int(base + 20 * 3600),
+            "finished_at": int(base + 20 * 3600 + 8),
+            "error": None,
+            "summary": {"folders": 2, "added": 65, "removed": 0, "ok": True},
+        },
+        "discovery": {
+            "name": "discovery", "ok": True,
+            "started_at": int(base + 21 * 3600),
+            "finished_at": int(base + 21 * 3600 + 24),
+            "error": None,
+            "summary": {
+                "searches": 4, "items": 168, "candidates": 4,
+                "notified": 3, "errors": [],
+            },
+        },
+        "candidate_cleanup": {
+            "name": "candidate_cleanup", "ok": True,
+            "started_at": int(base + 22 * 3600),
+            "finished_at": int(base + 22 * 3600 + 1),
+            "error": None,
+            "summary": {"candidates_removed": 0, "fav_actions_expired": 0},
+        },
+    }
+    for name, record in records.items():
+        conn.execute(
+            "INSERT OR REPLACE INTO kv(k, v) VALUES (?, ?)",
+            (f"task:last:{name}", json.dumps(record, ensure_ascii=False)),
+        )
+    conn.execute(
+        "INSERT OR REPLACE INTO kv(k, v) VALUES ('snapshot:last_attempt', ?)",
+        (latest_day.isoformat(),),
+    )
+    conn.execute(
+        "INSERT OR REPLACE INTO kv(k, v) VALUES ('snapshot:last_completed', ?)",
+        (latest_day.isoformat(),),
+    )
+    conn.execute(
+        "INSERT OR REPLACE INTO kv(k, v) VALUES (?, '1')",
+        (f"snapshot:backup:{latest_day.isoformat()}",),
+    )
+    conn.execute(
+        "INSERT OR REPLACE INTO kv(k, v) VALUES (?, '')",
+        (f"snapshot:backup_error:{latest_day.isoformat()}",),
+    )
+
+
 def _seed_blacklist(conn: sqlite3.Connection, now: float) -> None:
     conn.execute(
         """
@@ -495,6 +558,7 @@ def seed_preview(
             up_rows = _seed_up_stats(conn, latest_day, days, anomaly_rng)
             _seed_candidates(conn, latest_day)
             _seed_blacklist(conn, _timestamp(latest_day, hour=14))
+            _seed_task_records(conn, latest_day)
         else:
             up_rows = 0
             conn.execute("DELETE FROM candidate WHERE channel = 'preview'")
@@ -635,6 +699,12 @@ def main(argv: Sequence[str] | None = None) -> int:
             config_out=args.config_out,
             with_anomalies=not args.no_anomalies,
         )
+    except PermissionError as exc:
+        print(json.dumps({
+            "ok": False,
+            "error": f"目标数据库被占用，请先停止预览服务: {exc}",
+        }, ensure_ascii=False))
+        return 2
     except (ValueError, FileNotFoundError, FileExistsError, RuntimeError, sqlite3.Error) as exc:
         print(json.dumps({"ok": False, "error": str(exc)}, ensure_ascii=False))
         return 2