功能：实现桌面选择流程并接入 Moonlight 会话

变更详情：feat(kiosk-shell): 登录/桌面列表产品流程 + Moonlight 会话 + 看门狗进程组修复

- 登录页改为用户认证（本地演示认证，账号密码非空通过）
- 新增桌面列表页：Windows/Moonlight 可连接，Ubuntu/麒麟待分配
- 新增 DesktopService 适配层（登录/桌面列表/连接票据，后续接 API）
- 新增 MoonlightSession：QProcess 参数数组直启 moonlight-qt，退出回列表
- 状态机扩展 AUTHENTICATING / DESKTOP_LIST
- 移除开机自动 RDP，收敛为 monitor -> kiosk-shell 单一自启链
- Monitor 按进程组结束整棵进程树，修复孤儿串流进程
- vdi-moonlight 启动器新增 vsync/frame-pacing/overlay 低延迟开关

terminal/kiosk-shell/src/moonlight_session.cpp

@@ -0,0 +1,138 @@
+#include "moonlight_session.h"
+
+#include <QDate>
+#include <QDateTime>
+#include <QDir>
+#include <QFile>
+#include <QTextStream>
+
+namespace vdi {
+
+MoonlightSession::MoonlightSession(QObject* parent) : QObject(parent) {}
+
+MoonlightSession::~MoonlightSession() {
+    stop();
+}
+
+void MoonlightSession::setOptions(const Options& options) {
+    options_ = options;
+}
+
+bool MoonlightSession::isRunning() const {
+    return process_ && process_->state() != QProcess::NotRunning;
+}
+
+bool MoonlightSession::start(const ConnectionTicket& ticket, StateCallback callback) {
+    if (isRunning()) {
+        return false;
+    }
+    callback_ = std::move(callback);
+
+    // moonlight-qt 需要 X11 会话环境；由 kiosk-shell 继承当前 DISPLAY/XAUTHORITY
+    process_ = new QProcess(this);
+    process_->setProgram(QStringLiteral("moonlight-qt"));
+    process_->setProcessChannelMode(QProcess::MergedChannels);
+
+    QStringList args;
+    args << QStringLiteral("stream")
+         << ticket.endpoint
+         << ticket.app
+         << QStringLiteral("--resolution")
+         << QStringLiteral("%1x%2").arg(ticket.width).arg(ticket.height)
+         << QStringLiteral("--fps") << QString::number(ticket.fps)
+         << QStringLiteral("--bitrate") << QString::number(20000)
+         << QStringLiteral("--display-mode") << QStringLiteral("fullscreen")
+         << QStringLiteral("--video-codec") << options_.videoCodec
+         << QStringLiteral("--video-decoder") << options_.decoder
+         << QStringLiteral("--absolute-mouse")
+         << QStringLiteral("--keep-awake");
+    if (options_.vsync) {
+        args << QStringLiteral("--vsync");
+    } else {
+        args << QStringLiteral("--no-vsync");
+    }
+    if (options_.framePacing) {
+        args << QStringLiteral("--frame-pacing");
+    } else {
+        args << QStringLiteral("--no-frame-pacing");
+    }
+    if (options_.performanceOverlay) {
+        args << QStringLiteral("--performance-overlay");
+    }
+    if (options_.audioOnHost) {
+        args << QStringLiteral("--audio-on-host");
+    } else {
+        args << QStringLiteral("--no-audio-on-host");
+    }
+    process_->setArguments(args);
+
+    // 日志追加到 moonlight-yyyyMMdd.log，便于现场排查
+    const QString logDir =
+        QDir::homePath() + QStringLiteral("/vdi-terminal/logs");
+    QDir().mkpath(logDir);
+    const QString logPath = logDir + QStringLiteral("/moonlight-%1.log")
+        .arg(QDate::currentDate().toString(QStringLiteral("yyyyMMdd")));
+
+    connect(process_, &QProcess::finished, this, &MoonlightSession::onProcessFinished);
+    connect(process_, &QProcess::errorOccurred, this, &MoonlightSession::onProcessError);
+    connect(process_, &QProcess::readyReadStandardOutput, this, [this, logPath]() {
+        QFile log(logPath);
+        if (log.open(QIODevice::WriteOnly | QIODevice::Append | QIODevice::Text)) {
+            QTextStream(&log) << QString::fromUtf8(process_->readAllStandardOutput());
+        }
+    });
+
+    if (callback_) {
+        callback_(true, QStringLiteral("串流进程已启动"));
+    }
+    process_->start();
+    return true;
+}
+
+void MoonlightSession::onProcessFinished(int exitCode, QProcess::ExitStatus exitStatus) {
+    QString message;
+    if (exitStatus == QProcess::CrashExit) {
+        message = QStringLiteral("串流异常退出 (code=%1)").arg(exitCode);
+    } else {
+        message = QStringLiteral("串流已结束 (code=%1)").arg(exitCode);
+    }
+    process_->deleteLater();
+    process_ = nullptr;
+    if (callback_) {
+        callback_(false, message);
+    }
+}
+
+void MoonlightSession::onProcessError(QProcess::ProcessError error) {
+    QString message;
+    switch (error) {
+        case QProcess::FailedToStart:
+            message = QStringLiteral("无法启动 moonlight-qt，请检查安装");
+            break;
+        case QProcess::Crashed:
+            return;  // 由 finished(CrashExit) 统一上报
+        default:
+            message = QStringLiteral("串流进程错误 (%1)").arg(static_cast<int>(error));
+            break;
+    }
+    if (callback_) {
+        callback_(false, message);
+    }
+}
+
+void MoonlightSession::stop() {
+    if (!process_) {
+        return;
+    }
+    QProcess* proc = process_;
+    process_ = nullptr;  // 先断开自身引用，避免 finished 回调再触发状态迁移
+    disconnect(proc, nullptr, this, nullptr);
+    proc->terminate();
+    if (!proc->waitForFinished(2000)) {
+        proc->kill();
+        proc->waitForFinished(1000);
+    }
+    proc->deleteLater();
+}
+
+}  // namespace vdi