add: chat message reactions

crates/app/src/public/js/atto.js

@@ -688,6 +688,36 @@ media_theme_pref();
         $.OBSERVERS.push(observer);
     });
 
+    self.define("hooks::check_message_reactions", async ({ $ }) => {
+        const observer = $.offload_work_to_client_when_in_view(
+            async (element) => {
+                const reactions = await (
+                    await fetch(
+                        `/api/v1/message_reactions/${element.getAttribute("hook-arg:id")}`,
+                    )
+                ).json();
+
+                if (reactions.ok) {
+                    for (const reaction of reactions.payload) {
+                        element
+                            .querySelector(
+                                `[ui_ident=emoji_${reaction.emoji.replaceAll(":", "\\:")}]`,
+                            )
+                            .classList.remove("lowered");
+                    }
+                }
+            },
+        );
+
+        for (const element of Array.from(
+            document.querySelectorAll("[hook=check_message_reactions]") || [],
+        )) {
+            observer.observe(element);
+        }
+
+        $.OBSERVERS.push(observer);
+    });
+
     self.define("hooks::tabs:switch", (_, tab) => {
         tab = tab.split("?")[0];