fix: backup progress window + real-time rsync output

- Replace small popup with big backup progress window (750x500)
- Shows rsync command in header, real-time output in monospace textview
- Progress bar with percentage, Cancel/Close button
- Output with color-coded tags (error=red, success=green, cmd=gray italic)
- Auto-scrolls to bottom during backup
- Fixed live log not updating (stdbuf -oL for unbuffered rsync output)
- Fixed double closing brace compilation error
- Downloaded proper backup icon

src/main_window.h

@@ -28,22 +28,16 @@ private:
 	void build_ui();
 	void build_menu();
 	void build_toolbar();
-	void build_sidebar();
-	void build_file_browser();
 	void build_statusbar();
 
 	void refresh_snapshot_list();
-	void load_selected_snapshot();
 	void browse_path(const std::string& snapshot, const std::string& path);
 	void navigate_up();
 
-	void on_backup_clicked();
-	void on_restore_clicked();
-	void on_delete_snapshot_clicked();
-	void on_new_backup_clicked();
-
 	void show_sudo_dialog(std::function<void(const std::string&)> callback);
-	void show_progress_dialog(const std::string& title);
+	void open_backup_window(const std::string& description = "");
+	void close_backup_window();
+	void append_backup_line(const std::string& line, const char* tag = nullptr);
 
 	void install_cronjob();
 	void remove_cronjob();
@@ -80,22 +74,25 @@ private:
 	GtkWidget* file_tree_ = nullptr;
 	GtkWidget* path_entry_ = nullptr;
 	GtkWidget* statusbar_ = nullptr;
-	GtkWidget* progress_bar_ = nullptr;
-	GtkWidget* progress_label_ = nullptr;
-	GtkWidget* progress_window_ = nullptr;
 	GtkWidget* nav_label_ = nullptr;
 
 	GtkListStore* file_store_ = nullptr;
 	GtkWidget* toolbar_ = nullptr;
-	GtkWidget* log_window_ = nullptr;
-	GtkWidget* log_textview_ = nullptr;
-	guint log_timer_ = 0;
 
 	GtkWidget* live_log_textview_ = nullptr;
 	GtkWidget* live_log_label_ = nullptr;
 	GtkWidget* backlog_textview_ = nullptr;
 	GtkWidget* backlog_scrolled_ = nullptr;
 
+	/* Backup progress window */
+	GtkWidget* backup_win_ = nullptr;
+	GtkWidget* backup_cmd_label_ = nullptr;
+	GtkWidget* backup_output_view_ = nullptr;
+	GtkWidget* backup_progress_ = nullptr;
+	GtkWidget* backup_status_label_ = nullptr;
+	GtkWidget* backup_cancel_btn_ = nullptr;
+	GtkWidget* backup_close_btn_ = nullptr;
+
 	std::string log_path_;
 
 	std::string current_snapshot_;