Update DAWN app to free and refresh icon

Set the 'paid' status of DAWN for Mastodon to false in the apps list, indicating it is now free. Also updated the dawn.png icon in the public assets.

Author: noppefoxwolf

data/apps.ts

@@ -230,7 +230,7 @@ export const apps: appsList = {
       name: "DAWN for Mastodon",
       icon: dawn,
       url: "https://apps.apple.com/app/nightfox-dawn/id1668645019",
-      paid: true,
+      paid: false,
       open: false,
     },
     {