Replace Slint UI with UIKit and add milestones

Fixes #2.\nFixes #9.

AGENTS.md

@@ -1,5 +1,11 @@
 # Repository instructions
 
+## Gitea issue workflow
+
+Use the `tea` command-line tool as the preferred way to list, inspect, create,
+and update Gitea issues. Run it from the repository root so it can use the
+configured remote, for example `tea issues` or `tea issues 1`.
+
 ## Required pre-commit gates
 
 Run every gate below from the repository root before committing. Every command