refactor: archive GUI clients; keep minimal TUI with hooks/API

Move Qt/Tauri/full Web SPA under archive/, ship hermit as CLI/TUI plus
libcstcore and cst-webui/1 HTTP+SSE (turn lifecycle hooks, capabilities).

Co-authored-by: Cursor <cursoragent@cursor.com>

archive/qt-app/src/platform/windows/NotifyTool.cpp

@@ -0,0 +1,196 @@
+/* Platform tools on Windows, implemented by the app (not by the engine): they
+ * exist exactly where the desktop service does, and the engine only ever sees
+ * the capability -- platforms + probe decide whether the tool is offered.
+ *
+ * The Linux file next door is the same shape; what differs is the service
+ * behind each call. A notification is the scripting host's popup (Wscript.Shell
+ * through PowerShell) because Windows has no notify-send and a toast needs the
+ * WinRT API; it carries the same two arguments and answers the same way. */
+
+#include <QByteArray>
+#include <QClipboard>
+#include <QDesktopServices>
+#include <QFileInfo>
+#include <QGuiApplication>
+#include <QProcess>
+#include <QString>
+#include <QStringList>
+#include <QUrl>
+
+#include <cstdio>
+#include <cstring>
+
+#include "core/AgentCore.h"
+#include "core/ToolProvider.h"
+
+namespace app {
+namespace {
+
+/* whereis-style check without a shell: PATH is split on the Windows separator
+ * and a name may need one of the executable suffixes. */
+bool haveProgram(const char *name) {
+  const QByteArray path = qgetenv("PATH");
+  const QList<QByteArray> dirs = path.split(';');
+  const QList<QByteArray> exts = {QByteArray(), QByteArray(".exe"),
+                                  QByteArray(".cmd"), QByteArray(".bat")};
+  for (const QByteArray &d : dirs) {
+    if (d.isEmpty())
+      continue;
+    for (const QByteArray &ext : exts) {
+      const QString cand = QFileInfo(QString::fromLocal8Bit(d + "\\" + name +
+                                                           ext))
+                               .absoluteFilePath();
+      if (QFileInfo::exists(cand) && QFileInfo(cand).isExecutable())
+        return true;
+    }
+  }
+  return false;
+}
+
+/* 0 when notifications can be shown; -1 with the reason otherwise. */
+int notifyProbe(char *why, size_t why_sz) {
+  if (haveProgram("powershell") || haveProgram("pwsh"))
+    return 0;
+  snprintf(why, why_sz, "no powershell on PATH to show a popup with");
+  return -1;
+}
+
+const char *argOf(const ctl_tool_call_t *call, const char *key) {
+  for (int i = 0; i < call->nargs; i++)
+    if (strcmp(call->args[i].key, key) == 0)
+      return call->args[i].value;
+  return nullptr;
+}
+
+/* Runs on the turn's worker thread: no GUI objects here. The popup is started
+ * detached -- it waits for its own timeout, and the turn must not. */
+int notifyRun(const cst_tool_ctx_t *ctx, const ctl_tool_call_t *call,
+              cst_tool_result_t *r, void *ud) {
+  (void)ctx;
+  (void)ud;
+  const char *title = argOf(call, "title");
+  const char *message = argOf(call, "message");
+  if (!message || !message[0]) {
+    const char *msg = "error: notification_send needs a message";
+    r->out = strdup(msg);
+    r->out_len = r->out ? strlen(msg) : 0;
+    r->exit_code = 1;
+    return 0;
+  }
+  const QString shown =
+      title && title[0] ? QString::fromUtf8(title) : QStringLiteral("CST-agent");
+  /* The popup's own text is single-quoted for PowerShell; a quote inside it is
+   * doubled, which is how PowerShell escapes one. */
+  QString text = QString::fromUtf8(message);
+  text.replace(QLatin1Char('\''), QLatin1String("''"));
+  QString heading = shown;
+  heading.replace(QLatin1Char('\''), QLatin1String("''"));
+  const QString script =
+      QStringLiteral("$w = New-Object -ComObject Wscript.Shell; "
+                     "$w.Popup('%1', 8, '%2', 64) | Out-Null")
+          .arg(text, heading);
+  const QString exe = haveProgram("pwsh") ? QStringLiteral("pwsh")
+                                         : QStringLiteral("powershell");
+  QStringList args;
+  args << QStringLiteral("-NoProfile") << QStringLiteral("-NonInteractive")
+       << QStringLiteral("-Command") << script;
+  const bool started = QProcess::startDetached(exe, args);
+  const QByteArray out = started
+                             ? QByteArrayLiteral("notification shown")
+                             : QByteArrayLiteral("could not start ") +
+                                   exe.toLocal8Bit();
+  r->out = strdup(out.constData());
+  r->out_len = r->out ? strlen(r->out) : 0;
+  r->exit_code = started ? 0 : 1;
+  return 0;
+}
+
+/* Registered once; the engine keeps a copy until the owner is unregistered. */
+cst_tool_def_t g_notify;
+
+}  // namespace
+
+/* A file card's "open": ShellExecute through QDesktopServices, so the file's
+ * own application comes up. */
+QString openLocalFile(const QString &path, const QString &title,
+                      QString *status) {
+  const QString name = title.isEmpty() ? QFileInfo(path).fileName() : title;
+  if (qEnvironmentVariableIsSet("CST_APP_NO_OPEN")) {
+    if (status)
+      *status = QStringLiteral("opened %1 (test mode)").arg(name);
+    return QString();
+  }
+  if (!QFileInfo::exists(path))
+    return QStringLiteral("the file is gone: %1").arg(name);
+  if (!QDesktopServices::openUrl(QUrl::fromLocalFile(path)))
+    return QStringLiteral("no application on this machine opens %1").arg(name);
+  if (status)
+    *status = QStringLiteral("opened %1").arg(name);
+  return QString();
+}
+
+/* No share sheet here: the path is what another program needs, so it goes to
+ * the clipboard. */
+QString shareLocalFile(const QString &path, const QString &title,
+                       QString *status) {
+  const QString name = title.isEmpty() ? QFileInfo(path).fileName() : title;
+  if (qEnvironmentVariableIsSet("CST_APP_NO_OPEN")) {
+    if (status)
+      *status = QStringLiteral("shared %1 (test mode)").arg(name);
+    return QString();
+  }
+  if (!QFileInfo::exists(path))
+    return QStringLiteral("the file is gone: %1").arg(name);
+  QGuiApplication::clipboard()->setText(path);
+  if (status)
+    *status = QStringLiteral("%1: the path is on the clipboard").arg(name);
+  return QString();
+}
+
+/* Windows does not freeze a process whose window is open, and the app's own
+ * window is what keeps it alive: nothing to hold. */
+QString holdForeground(const QString &text) {
+  (void)text;
+  return QString();
+}
+void releaseForeground() {}
+
+/* A native file dialog hands over a path, so there is nothing to turn into
+ * one: a file:// URL loses its scheme and anything else is taken as a path. */
+QString materializeAttachment(const QString &pathOrUri, QString *err) {
+  (void)err;
+  QString s = pathOrUri;
+  if (s.startsWith(QLatin1String("file://")))
+    s = s.mid(7);
+  return s;
+}
+
+/* Every process on Windows reads the files its user can. */
+bool hasAllFilesAccess() { return true; }
+QString requestAllFilesAccess() { return QString(); }
+
+/* A Windows window has its own frame; there is no system bar drawn over it. */
+QString requestFullscreen() { return QString(); }
+
+int platformRegisterWindows(AgentCore *core) {
+  static const cst_tool_param_t params[CST_TOOL_MAX_PARAMS] = {
+      {"message", "string", 1, "text of the notification"},
+      {"title", "string", 0, "title line (default: CST-agent)"},
+      {nullptr, nullptr, 0, nullptr},
+      {nullptr, nullptr, 0, nullptr},
+      {nullptr, nullptr, 0, nullptr},
+      {nullptr, nullptr, 0, nullptr}};
+  memset(&g_notify, 0, sizeof(g_notify));
+  setMeta(&g_notify, "notification_send",
+          "Show a notification outside the window (a popup that goes away by "
+          "itself).",
+          CST_TP_ASK, "notify", kDesktopOnly, notifyProbe);
+  memcpy(g_notify.params, params, sizeof(params));
+  g_notify.run = nullptr;
+  g_notify.run_ex = notifyRun;
+  g_notify.ud = nullptr;
+  g_notify.owner = "app:windows";
+  return core->registerTool(&g_notify) ? 1 : 0;
+}
+
+}  // namespace app