Add threaded session backend architecture with real SSH backend

src/session_tab.h

@@ -0,0 +1,67 @@
+#ifndef ORBITHUB_SESSION_TAB_H
+#define ORBITHUB_SESSION_TAB_H
+
+#include "profile_repository.h"
+#include "session_backend.h"
+
+#include <QWidget>
+
+#include <optional>
+
+class QLabel;
+class QPlainTextEdit;
+class QPushButton;
+class QThread;
+class SessionBackend;
+
+class SessionTab : public QWidget
+{
+    Q_OBJECT
+
+public:
+    explicit SessionTab(const Profile& profile, QWidget* parent = nullptr);
+    ~SessionTab() override;
+
+    QString tabTitle() const;
+
+signals:
+    void tabTitleChanged(const QString& title);
+    void requestConnect(const SessionConnectOptions& options);
+    void requestDisconnect();
+    void requestReconnect(const SessionConnectOptions& options);
+
+private slots:
+    void onConnectClicked();
+    void onDisconnectClicked();
+    void onReconnectClicked();
+    void onCopyErrorClicked();
+
+    void onBackendStateChanged(SessionState state, const QString& message);
+    void onBackendEventLogged(const QString& message);
+    void onBackendConnectionError(const QString& displayMessage, const QString& rawMessage);
+
+private:
+    Profile m_profile;
+    QThread* m_backendThread;
+    SessionBackend* m_backend;
+    SessionState m_state;
+    QString m_lastError;
+
+    QLabel* m_statusLabel;
+    QLabel* m_errorLabel;
+    QPlainTextEdit* m_eventLog;
+    QPushButton* m_connectButton;
+    QPushButton* m_disconnectButton;
+    QPushButton* m_reconnectButton;
+    QPushButton* m_copyErrorButton;
+
+    void setupUi();
+    std::optional<SessionConnectOptions> buildConnectOptions();
+    bool validateProfileForConnect();
+    void appendEvent(const QString& message);
+    void setState(SessionState state, const QString& message);
+    QString stateSuffix() const;
+    void refreshActionButtons();
+};
+
+#endif