v1.3.0

Fix the broken delete (route param was read from the wrong source -> every delete 404'd). Internal rewrite to Flarum 2.0 conventions: a proper API resource + policy (the API moves from /api/shoutbox to /api/shouts) and a TypeScript frontend using ES module imports. Also bounds the shouts table to the newest 500 rows. No visible change to how the shoutbox works.