Duplicate flow not accounted for in tracked change results

[wotbrew]

The problem @isaksky (🙏 ) raised on slack involves duplication in the tracked :added / :deleted vectors.

I think :added & :deleted might want to be sets as duplicates during flow are permitted, unless there is some otherway to distinct the adds during tracking.

(let [num-schema [[:from :nums]
                    [:constrain
                     [:check [number? :n]]
                     [:unique :id]]]
        watched-query (into num-schema
                        [[:where [= :id 1]
                          ;; Try removing this form, the second entry in the result vector does not appear without it
                          [< 1 [rel/env :now]]]
                         [:extend
                          [:hm [- :n [rel/env :now]]]]])
        db (-> (rel/transact {}
                 (for [i (range 1 1e2)]
                   [:insert :nums {:id i, :n i}]))
             (rel/with-env {:now (inst-ms (java.time.Instant/now))})
             (rel/mat num-schema)
             (rel/watch watched-query))]
    (->> (get-in
           (rel/track-transact
             db
             (rel/set-env-tx {:now (+ (inst-ms (java.time.Instant/now)) 5)}))
           [:changes watched-query :added])))
;; => 
[{:id 1, :n 1, :hm -1701901820800} {:id 1, :n 1, :hm -1701901820800}]