Provide stable keys for components in lists

See https://preactjs.com/tutorial/08-keys/

src/computersandblues/lodestone/app.cljs

@@ -415,10 +415,11 @@
      [:time.date {:datetime (:created_at post)} (first (str/split (:created_at post) "T"))]]]
    [:section.content {:dangerouslySetInnerHTML (r/unsafe-html (:content post))}]
    (when (seq (:media_attachments post))
-     [:section.attachments
-      (map-indexed (fn [idx item]
-                     ^{:key idx} [attachment {:attachment item}])
-                   (:media_attachments post))])
+     (into [:section.attachments]
+           (map (fn [item]
+                  (let [key (str "post-" (:id post) "-attachment-" (:id item))]
+                    ^{:key key} [attachment {:attachment item}])))
+           (:media_attachments post)))
    [:nav
     [:ul.controls
      [:li.control-element.url
@@ -519,8 +520,11 @@
       [:section.buttons
        [:button.control-button {:on-click fetch-more-posts! :disabled (boolean (seq loading))} "⇓ Fetch more"]
        [:button.control-button {:on-click disconnect-account!} "▤ Disconnect account"]]]
-     [:ul.results (map-indexed (fn [idx p]
-                                 ^{:key idx} [:li.result [post {:post p}]]) displayed-posts)]]))
+     (into [:ul.results]
+           (map (fn [p]
+                  (let [key (str "post-" (:id p))]
+                    ^{:key key} [:li.result [post {:post p}]])))
+           displayed-posts)]))
 
 ;; help section