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/twitter/HAND.toml

@@ -2,6 +2,11 @@ id = "twitter"
 version = "1.0.0"
 name = "Twitter Hand"
 description = "Autonomous Twitter/X manager — content creation, scheduled posting, engagement, and performance tracking"
+
+[i18n.zh]
+name = "Twitter Hand"
+description = "自主 Twitter/X 管理——内容创作、定时发布、互动管理和效果追踪"
+
 category = "communication"
 icon = "\U0001D54F"
 tools = [