badges: service group with multi-use codes (#7578)

* core: cancel the chat callback on interrupt

* badges: add multi-use codes

* badges: add the managed group

* badges: document multi-use codes and the group

* core: sign test badges with whole-second expiry

* badges: rework tracker and reply texts

scripts/badge-service/badge_service.ini.example

@@ -42,5 +42,13 @@ idle_seconds = 60
 index = 1
 private_key = replace-me
 
-[dev]
-chat_redeem = on
+; Optional. When present, the service creates and manages one group on its first
+; start without --run-cli, and logs its join link once, on the start that creates it.
+; The link is a bearer secret that stays valid, so keep that log private. The first
+; member to join is promoted to owner, so join right away.
+; Moderators can /issue and /bulk codes; admins and owners can also /revoke.
+; display_name must be a name the chat core accepts unchanged: one it would spell
+; differently stops the whole service, payments included, from starting.
+;[group]
+;display_name = SimpleX Badges
+;description = Welcome to the badges group