Improve terminal theming, cursor UX, and size negotiation

src/ssh_session_backend.h

@@ -21,6 +21,7 @@ public slots:
     void reconnectSession(const SessionConnectOptions& options) override;
     void sendInput(const QString& input) override;
     void confirmHostKey(bool trustHost) override;
+    void updateTerminalSize(int columns, int rows) override;
 
 private slots:
     void onProcessStarted();
@@ -43,6 +44,8 @@ private:
     bool m_waitingForPasswordPrompt;
     bool m_waitingForHostKeyConfirmation;
     bool m_passwordSubmitted;
+    int m_terminalColumns;
+    int m_terminalRows;
 
     void setState(SessionState state, const QString& message);
     bool startSshProcess(const SessionConnectOptions& options);
@@ -52,6 +55,7 @@ private:
     void cleanupAskPassScript();
     QString mapSshError(const QString& rawError) const;
     QString knownHostsFileForNullDevice() const;
+    void applyTerminalSizeIfAvailable();
 };
 
 #endif