✨ feat(native-window): 支持标签页拖出为原生独立窗口

- 支持 SQL、数据和结果标签拖出到跨显示器原生窗口
- 通过受认证 loopback bridge 复用主进程后端与状态
- 支持子窗口继续拆窗、聚焦、关闭、还原与异常退出恢复
- 补充多窗口协议、状态同步和跨平台回归测试

internal/nativewindow/process.go

@@ -0,0 +1,59 @@
+package nativewindow
+
+import (
+	"os"
+	"os/exec"
+)
+
+type processSpec struct {
+	Executable string
+	Env        []string
+}
+
+type childProcess interface {
+	PID() int
+	Wait() error
+	Kill() error
+}
+
+type processStarter interface {
+	Start(processSpec) (childProcess, error)
+}
+
+type execProcessStarter struct{}
+
+func (execProcessStarter) Start(spec processSpec) (childProcess, error) {
+	command := exec.Command(spec.Executable, DetachedWindowArgument)
+	command.Env = spec.Env
+	command.Stdout = os.Stdout
+	command.Stderr = os.Stderr
+	if err := command.Start(); err != nil {
+		return nil, err
+	}
+	return &execChildProcess{command: command}, nil
+}
+
+type execChildProcess struct {
+	command *exec.Cmd
+}
+
+func (p *execChildProcess) PID() int {
+	if p == nil || p.command == nil || p.command.Process == nil {
+		return 0
+	}
+	return p.command.Process.Pid
+}
+
+func (p *execChildProcess) Wait() error {
+	if p == nil || p.command == nil {
+		return nil
+	}
+	return p.command.Wait()
+}
+
+func (p *execChildProcess) Kill() error {
+	if p == nil || p.command == nil || p.command.Process == nil {
+		return nil
+	}
+	return p.command.Process.Kill()
+}