备份与迷雾的差异分析、合并执行，附属数据改挂坐标键

备份（.rondbackup）与迷雾（.fwss）各加一层「先看差异再动手」：

- 迷雾：上传先出差异页，说清叠加能补多少、整体替换会丢多少，并在真实底图上
  用绿/灰/红标出会新增 / 不变 / 会丢的区域
- 备份：与当前数据集按 UUID 逐条比对（rond 每次导出都会重排 Z_PK，编号认不出人），
  新增合入、冲突逐条选、仅站内有逐条勾选删除，全在一个事务里执行；
  合入的行写回 entity_raw，保证再传同一份备份时差异归零
- 地点按坐标对齐：站点的「补全地址」会把地点改名，拿名称当键会让一整个地点的
  到访全变成假冲突
- 附属数据（备注/结论/访客票/图片）从 dataset_id+src_pk 换成坐标键，换数据集不再失联；
  访客票没有 dataset_id，回填按活跃数据集认领
- 修正 contentHash 拿 Z_PK 当指纹的隐患，以及两处「src_pk 跨快照稳定」的错误注释

导出格式（.rondbackup / .fwss）保持原样，往返测试通过。

internal/web/handlers_vote.go

@@ -102,12 +102,12 @@ func (s *Server) apiVotes(w http.ResponseWriter, r *http.Request) {
 		s.json(w, map[string]string{"error": err.Error()})
 		return
 	}
-	tallies, err := s.votes.Tallies(ctx)
+	tallies, err := s.votes.Tallies(ctx, votesDatasetID)
 	if err != nil {
 		s.json(w, map[string]string{"error": err.Error()})
 		return
 	}
-	mine, err := s.votes.VoterAll(ctx, s.voterKeyFromRequest(r))
+	mine, err := s.votes.VoterAll(ctx, votesDatasetID, s.voterKeyFromRequest(r))
 	if err != nil {
 		s.json(w, map[string]string{"error": err.Error()})
 		return
@@ -145,10 +145,16 @@ func (s *Server) apiVerdict(w http.ResponseWriter, r *http.Request) {
 
 // apiVote 记录访客对某地点的点赞 / 点踩，返回最新票数与该访客的选择。
 func (s *Server) apiVote(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
 	if err := r.ParseForm(); err != nil {
 		s.json(w, map[string]string{"error": "请求解析失败"})
 		return
 	}
+	ds, err := s.datasetFor(ctx)
+	if err != nil || ds == nil {
+		s.json(w, map[string]string{"error": "还没有可投票的数据集"})
+		return
+	}
 	srcPK, err := strconv.Atoi(r.PostFormValue("src_pk"))
 	vote, _ := strconv.Atoi(r.PostFormValue("vote"))
 	if err != nil || (vote != 1 && vote != -1) {
@@ -160,7 +166,7 @@ func (s *Server) apiVote(w http.ResponseWriter, r *http.Request) {
 		s.json(w, map[string]string{"error": "无法识别访客"})
 		return
 	}
-	t, mine, err := s.votes.Cast(r.Context(), srcPK, key, vote)
+	t, mine, err := s.votes.Cast(ctx, ds.ID, srcPK, key, vote)
 	if err != nil {
 		s.json(w, map[string]string{"error": err.Error()})
 		return
@@ -170,11 +176,17 @@ func (s *Server) apiVote(w http.ResponseWriter, r *http.Request) {
 
 // voteTotals 汇总站长结论数量与访客票数，供统计页展示。
 func (s *Server) voteTotals(ctx context.Context, datasetID int64) (rec, avoid, up, down int, err error) {
+	// 两张票表都挂坐标键，统计要按「本数据集的地点」圈定范围，
+	// 不能再按它们自己的 dataset_id 过滤——那个只是最后写入时留下的线索。
 	err = s.db.QueryRowContext(ctx, `SELECT
-		(SELECT count(*) FROM place_votes WHERE dataset_id=$1 AND verdict=1),
-		(SELECT count(*) FROM place_votes WHERE dataset_id=$1 AND verdict=-1),
-		(SELECT count(*) FROM place_visitor_votes WHERE vote=1),
-		(SELECT count(*) FROM place_visitor_votes WHERE vote=-1)`, datasetID).
+		(SELECT count(*) FROM place_votes v JOIN places p ON v.place_key = `+placeKeyExpr+`
+			WHERE p.dataset_id=$1 AND v.verdict=1),
+		(SELECT count(*) FROM place_votes v JOIN places p ON v.place_key = `+placeKeyExpr+`
+			WHERE p.dataset_id=$1 AND v.verdict=-1),
+		(SELECT count(*) FROM place_visitor_votes vv JOIN places p ON vv.place_key = `+placeKeyExpr+`
+			WHERE p.dataset_id=$1 AND vv.vote=1),
+		(SELECT count(*) FROM place_visitor_votes vv JOIN places p ON vv.place_key = `+placeKeyExpr+`
+			WHERE p.dataset_id=$1 AND vv.vote=-1)`, datasetID).
 		Scan(&rec, &avoid, &up, &down)
 	return
 }
@@ -183,7 +195,7 @@ func (s *Server) voteTotals(ctx context.Context, datasetID int64) (rec, avoid, u
 func (s *Server) verdictPlaces(ctx context.Context, datasetID int64, verdict, limit int) ([]stats.Place, error) {
 	q := `SELECT ` + stats.PlaceCols + ` FROM places p
 		WHERE p.dataset_id=$1 AND EXISTS (SELECT 1 FROM place_votes pv
-			WHERE pv.src_pk=p.src_pk AND pv.dataset_id=p.dataset_id AND pv.verdict=$2)
+			WHERE pv.place_key = ` + placeKeyExpr + ` AND pv.verdict=$2)
 		ORDER BY p.visit_count DESC LIMIT ` + strconv.Itoa(limit)
 	rows, err := s.db.QueryContext(ctx, q, datasetID, verdict)
 	if err != nil {