Merge upstream/main into belt-printer

Brings belt-printer up to main 4b4a261787. Resolutions:

- G-code header (#15897, #15915): main moved the header, config and
  thumbnail block later in _do_export; write_belt_header() moves with it,
  still after the thumbnails and outside the BTT_TFT gate.
- _extrude: first-layer acceleration keeps the per-path first-layer plane
  test with main's cached nozzle index (#16028); main's set_speed out-param
  form (#16108) everywhere else.
- GCodeWriter (#16108): the arc-to-polyline fallback for machine mappings
  that cannot express G2/G3 now runs in the out-param extrude_arc_to_xy,
  which is the overload GCode calls, and appends to the caller's string.
- GCodeProcessorResult: the belt fields join main's forwarding assign.
- Clipper2 (#15969): belt arrange helpers take Slic3r::Point; the tree
  support join types lose their ClipperLib qualifier.
- CLI arrange (#15837): belt printers still reserve no wipe tower.
- Wipe tower options (#15841): the two new sparse-layer toggles are hidden
  for belt printers like the rest of the tower options.
- Keyboard shortcuts (#15706): main's registry replaces the old key switch;
  the belt view toggle is re-registered in the next commit.
- Print::process: the belt purge-plan undo runs before main's SliceStarted
  event.
- scripts/filament_id_snapshot.json: deleted on main (a77209af8f).
- Includes and appended tests: union of both sides.

src/slic3r/GUI/Jobs/ArrangeJob.cpp

@@ -13,11 +13,32 @@
 #include "slic3r/GUI/NotificationManager.hpp"
 #include "slic3r/GUI/format.hpp"
 #include "slic3r/GUI/GUI_ObjectList.hpp"
+#include "slic3r/plugin/PluginManager.hpp"
 
 #include "libnest2d/common.hpp"
+#include "libslic3r/Arrange.hpp"
+#include <utility>
+#include "libslic3r/Point.hpp"
+#include "libslic3r/Polygon.hpp"
+#include <boost/log/trivial.hpp>
+#include <cstddef>
+#include <vector>
+#include "slic3r/GUI/Selection.hpp"
+#include "slic3r/GUI/Gizmos/GLGizmoBase.hpp"
+#include <set>
+#include <algorithm>
+#include "libslic3r/PrintConfig.hpp"
+#include <map>
+#include <cassert>
+#include "slic3r/GUI/Jobs/Job.hpp"
+#include "libslic3r/ExPolygon.hpp"
+#include "libslic3r/libslic3r.h"
+#include <numeric>
+#include <exception>
+#include "libslic3r/LifecycleEvents.hpp"
+#include <optional>
 #include "libslic3r/Geometry.hpp"
 #include <cmath>
-#include <set>
 
 #define SAVE_ARRANGE_POLY 0
 
@@ -780,6 +801,13 @@ void ArrangeJob::finalize(bool canceled, std::exception_ptr &eptr) {
         BOOST_LOG_TRIVIAL(debug) << __FUNCTION__ << boost::format(":arrange m_unprintable: name: %4%, bed_id %1%, trans {%2%,%3%}") % ap.bed_idx % unscale<double>(ap.translation(X)) % unscale<double>(ap.translation(Y)) % ap.name;
     }
 
+    {
+        Slic3r::LifecycleEventContext ctx;
+        ctx.code = Slic3r::LifecycleEvtCode::Ok;
+        ctx.msg = "arranged";
+        Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::ObjectTransformed, ctx);
+    }
+
     m_plater->update();
     // BBS
     //wxGetApp().obj_manipul()->set_dirty();