fix: LLM 工具循环 400、中断消息注入、ConPTY 终端支持

- agent: 工具轮请求尾部补 user 占位(zen 网关强制),tool 消息正确配对
- agent: 工具提醒/中断以 system 角色注入并带 [中断消息] 前缀,不进用户履历;系统提示词说明中断消息格式
- agentcli: 基于 ConPTY 的交互式终端(ptywin fork),terminal_create/read/write/resize/close/watch
- webui: server 输出通道适配器(保留 reasoning_content/disable_thinking)
- GUI: 沉浸式标题栏、icon 圆角重制、mascot 等打磨

internal/lua/vm.go

@@ -558,6 +558,7 @@ func (v *VM) writeBundledAdapters() error {
 	known := []string{
 		"openai", "anthropic", "deepseek", "gemini",
 		"github", "groq", "mistral", "ollama", "kimicode",
+		"server",
 	}
 	for _, name := range known {
 		srcPath := "adapters/" + name + ".lua"