ensure we dont collect hourly snapshot too soon after startup

internal/report/snapshots.go

@@ -361,6 +361,38 @@ ORDER BY snapshot_time ASC, table_name ASC
 	return records, rows.Err()
 }
 
+func LatestSnapshotTime(ctx context.Context, database db.Database, snapshotType string) (time.Time, error) {
+	dbConn := database.DB()
+	driver := strings.ToLower(dbConn.DriverName())
+
+	var maxTime sql.NullInt64
+	switch driver {
+	case "sqlite":
+		if err := dbConn.GetContext(ctx, &maxTime, `
+SELECT MAX(snapshot_time)
+FROM snapshot_registry
+WHERE snapshot_type = ?
+`, snapshotType); err != nil {
+			return time.Time{}, err
+		}
+	case "pgx", "postgres":
+		if err := dbConn.GetContext(ctx, &maxTime, `
+SELECT MAX(snapshot_time)
+FROM snapshot_registry
+WHERE snapshot_type = $1
+`, snapshotType); err != nil {
+			return time.Time{}, err
+		}
+	default:
+		return time.Time{}, fmt.Errorf("unsupported driver for listing snapshots: %s", driver)
+	}
+
+	if !maxTime.Valid || maxTime.Int64 <= 0 {
+		return time.Time{}, nil
+	}
+	return time.Unix(maxTime.Int64, 0), nil
+}
+
 func FormatSnapshotLabel(snapshotType string, snapshotTime time.Time, tableName string) string {
 	switch snapshotType {
 	case "hourly":