feat: issue skill

skills/use/SKILL.md

@@ -53,6 +53,10 @@ Config lives in `$XDG_CONFIG_HOME/tea`.
 - [HELPERS](references/tea/helpers.md) — open, notifications, clone, api
 - [MISC](references/tea/misc.md) — whoami, admin
 - [SETUP](references/tea/setup.md) — logins, logout, ssh-keys
+- [ISSUE FORMAT](references/issue-format.md) — canonical issue format: types
+  (`type/bug|feature|refactor` exclusive labels), templates, title and
+  language rules. MANDATORY whenever creating or editing an issue; the
+  `/tea:issue` skill is the guided procedure for it.
 
 ## Rich payloads — write to `$PWD/tmp/` first, then `tea api`