feat(i18n): add Chinese translations for all 14 hands

Add [i18n.zh] sections with localized name and description to every
HAND.toml in the registry.

hands/reddit/HAND.toml

@@ -2,6 +2,11 @@ id = "reddit"
 version = "1.0.0"
 name = "Reddit Hand"
 description = "Autonomous Reddit manager — monitors subreddits, posts content, replies to threads, and tracks karma and engagement"
+
+[i18n.zh]
+name = "Reddit Hand"
+description = "自主 Reddit 管理——监控子版块、发布内容、回复帖子并追踪 Karma 和互动"
+
 category = "communication"
 icon = "\U0001F4E2"
 tools = [