Skip muted-group messages to avoid wasting tokens

When the bot is muted in a group it cannot send replies, so process
nothing: short-circuit in onMessage before any trigger/LLM work using
Group.botMuteRemaining.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

src/main/kotlin/JChatGPT.kt

@@ -196,6 +196,11 @@ object JChatGPT : KotlinPlugin(
     private suspend fun onMessage(event: MessageEvent) {
         // 检查Token是否设置
         if (LargeLanguageModels.chat == null) return
+        // 如果bot在群里被禁言，则无法发言，直接结束，避免浪费token
+        if (event is GroupMessageEvent && event.group.botMuteRemaining > 0) {
+            logger.info("bot 在群 ${event.group.name}(${event.group.id}) 被禁言，剩余 ${event.group.botMuteRemaining} 秒，忽略消息")
+            return
+        }
         // 发送者是否有权限
         if (!event.toCommandSender().hasPermission(chatPermission)) {
             if (event is GroupMessageEvent) {