fix: 工具名过滤、消息拆分提示词优化

- filterActions: 过滤DeepSeek直接输出工具名(如vision_analyze)的怪话
- 系统提示词: 明确告知用双换行(空行)拆分多条消息
- 群聊规则: 加入独立想法用双换行分隔的说明

backend/platform-bridge/cmd/main.go

@@ -960,7 +960,27 @@ func filterActions(text string) string {
 		}
 	}
 
-	return strings.TrimSpace(text)
+	// 过滤 LLM 直接输出工具名的情况（DeepSeek 有时不调用函数而是直接输出函数名）
+	text = strings.TrimSpace(text)
+	toolNames := []string{"vision_analyze", "video_analyze", "web_search", "web_fetch",
+		"iot_control", "iot_query", "host_exec", "os_exec", "knowledge_search"}
+	for _, name := range toolNames {
+		if text == name || strings.HasPrefix(text, name+"\n") || strings.HasPrefix(text, name+"：") || strings.HasPrefix(text, name+":") {
+			text = strings.TrimPrefix(text, name)
+			text = strings.TrimSpace(text)
+			if text == "" {
+				return "" // 纯工具名，完全去掉
+			}
+		}
+	}
+	// 也处理 "vision_analyze\n..." 这种内嵌在第一行的情况
+	for _, name := range toolNames {
+		if strings.HasPrefix(text, name+" ") {
+			text = strings.TrimSpace(text[len(name):])
+		}
+	}
+
+	return text
 }
 
 // buildMemoryNamespace creates a memory-isolated user_id for a platform channel.

backend/platform-bridge/internal/handler/bridge_handler.go

@@ -309,7 +309,16 @@ func filterActions(text string) string {
 			text = text[:start] + text[start+end+len(closeTag):]
 		}
 	}
-	return strings.TrimSpace(text)
+	// 过滤 LLM 直接输出工具名的情况（DeepSeek 有时不调用函数而是直接输出函数名）
+	text = strings.TrimSpace(text)
+	toolNames := []string{"vision_analyze", "video_analyze", "web_search", "web_fetch",
+		"iot_control", "iot_query", "host_exec", "os_exec", "knowledge_search"}
+	for _, name := range toolNames {
+		if text == name || strings.HasPrefix(text, name+"\n") || strings.HasPrefix(text, name+"：") || strings.HasPrefix(text, name+":") {
+			return ""
+		}
+	}
+	return text
 }
 
 // convertMarkdownPlain strips basic markdown formatting.