Reserve the Prime Tower When the CLI Arranges a Project

The global arrange branch, taken by --arrange with all plates selected, only
reserved the prime tower when filament ids had been given on the command
line for STL input. A project carries its filament use per plate and its own
tower positions, but that set was empty for it, so the tower was never an
obstacle: the arranged pile was centred over it and the slice then failed on
a G-code path conflict.

When no filament ids were given, count the filaments each plate uses and
reserve a tower on every plate that needs one, keeping the project's tower
position instead of resetting it to the default. Only a tower the slicer will
print is reserved: the prime tower must be enabled, and a by-object print
gets none unless a smooth timelapse needs it, as the per-plate arrange
decides. Overflow beds are sized for the busiest plate. The STL route is
unchanged.

src/OrcaSlicer.cpp

@@ -5520,12 +5520,28 @@ int CLI::run(int argc, char **argv)
                     //add the virtual object into unselect list if has
                     partplate_list.preprocess_exclude_areas(unselected, enable_wrapping_detect);
 
-                    if (used_filament_set.size() > 0)
+                    // Filament ids given on the command line size the tower for STL input. A project
+                    // records its filament use per plate, so count there and keep its tower positions.
+                    const int  plate_count  = partplate_list.get_plate_count();
+                    const bool from_project = used_filament_set.empty();
+                    std::vector<int> plate_filament_counts(plate_count, static_cast<int>(used_filament_set.size()));
+                    if (from_project)
+                        for (int plate_index = 0; plate_index < plate_count; ++plate_index)
+                            plate_filament_counts[plate_index] = static_cast<int>(partplate_list.get_plate(plate_index)->get_extruders_under_cli(true, m_print_config).size());
+                    // A project only gets a tower the slicer will print: the prime tower enabled, and not
+                    // a by-object print unless a smooth timelapse needs it, as the per-plate arrange decides.
+                    const bool project_tower_allowed = m_print_config.option<ConfigOptionBool>("enable_prime_tower", true)->value &&
+                                                       (is_smooth_timelapse || !arrange_cfg.is_seq_print);
+                    const auto plate_needs_wipe_tower = [from_project, project_tower_allowed, is_smooth_timelapse](int filament_count) {
+                        if (!from_project)
+                            return filament_count > 0;
+                        return project_tower_allowed && (filament_count > 1 || (filament_count > 0 && is_smooth_timelapse));
+                    };
+                    const int max_filament_count = plate_count > 0 ? *std::max_element(plate_filament_counts.begin(), plate_filament_counts.end()) : 0;
+
+                    if (plate_needs_wipe_tower(max_filament_count))
                     {
                         //prepare the wipe tower
-                        int plate_count = partplate_list.get_plate_count();
-                        int extruder_size = used_filament_set.size();
-
                         auto printer_structure_opt = m_print_config.option<ConfigOptionEnum<PrinterStructure>>("printer_structure");
                         // This margin only pre-adjusts the default away from the near edges;
                         // estimate_wipe_tower_polygon below computes the real clamped position.
@@ -5561,7 +5577,11 @@ int CLI::run(int argc, char **argv)
 
                         for (int bedid = 0; bedid < MAX_PLATE_COUNT; bedid++) {
                             int plate_index_valid = std::min(bedid, plate_count - 1);
-                            if (bedid < plate_count) {
+                            // Overflow beds may receive objects from any plate, so size them for the busiest one.
+                            const int extruder_size = bedid < plate_count ? plate_filament_counts[bedid] : max_filament_count;
+                            if (!plate_needs_wipe_tower(extruder_size))
+                                continue;
+                            if (bedid < plate_count && !from_project) {
                                 wipe_x_option->set_at(&wt_x_opt, plate_index_valid, 0);
                                 wipe_y_option->set_at(&wt_y_opt, plate_index_valid, 0);
                             }