Add Missing Includes Across src/slic3r/GUI (#16048)

* Add Missing Includes Across src/slic3r/GUI

Every GUI source and header now directly includes the headers declaring what it uses, rather than relying on the precompiled header or transitive includes. Generated with clang-tidy misc-include-cleaner, plus one hand edit making CalibrationPanel.hpp self-contained.

* Drop the OS-Specific Includes Added Outside Their Platform Guards

GLib, GTK, D-Bus and POSIX headers are only used inside platform #if blocks, which already include them. Added unconditionally at the top of the file they broke the Windows build.

* Add the clang-tidy Configuration That Generated These Includes

Only misc-include-cleaner's missing-include check, with the headers it must never suggest: per-platform, internal and OS-specific ones that would break other platforms or are not meant to be included directly.

* Match Windows Paths in the clang-tidy Ignore List

Header paths use backslashes on Windows, so every / in a pattern is now [/\\]. The Windows SDK headers are ignored alongside the other OS-specific ones, and the list is one pattern per line. Suggested by @raistlin7447 from a Windows clang-cl run.

src/slic3r/GUI/3DScene.cpp

@@ -1,3 +1,7 @@
+#include <array>
+#include <algorithm>
+#include <functional>
+#include <cmath>
 #include <glad/gl.h>
 
 #include "3DScene.hpp"
@@ -25,6 +29,30 @@
 #include "libslic3r/Tesselate.hpp"
 #include "libslic3r/PrintConfig.hpp"
 
+#include "libslic3r/BoundingBox.hpp"
+#include "libslic3r/TriangleMeshSlicer.hpp"
+#include "libslic3r/Polygon.hpp"
+#include "libslic3r/Point.hpp"
+#include "slic3r/GUI/ImGuiWrapper.hpp"
+#include "libslic3r/Model.hpp"
+#include "libslic3r/Technologies.hpp"
+#include <optional>
+#include "slic3r/GUI/OpenGLManager.hpp"
+#include "libslic3r/Config.hpp"
+#include <memory>
+#include "slic3r/GUI/MeshUtils.hpp"
+#include "libslic3r/TriangleMesh.hpp"
+#include <math.h>
+#include "libslic3r/ObjectID.hpp"
+#include "libslic3r/libslic3r.h"
+#include <map>
+#include <set>
+#include <iterator>
+#include "libslic3r/Color.hpp"
+#include "slic3r/GUI/GUI_ObjectList.hpp"
+#include "libslic3r/Line.hpp"
+#include "libslic3r/Polyline.hpp"
+#include "libslic3r/Exception.hpp"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -36,6 +64,9 @@
 #include <boost/algorithm/string/predicate.hpp>
 
 #include <Eigen/Dense>
+#include <vector>
+#include <utility>
+#include <string>
 
 #ifdef HAS_GLSAFE
 void glAssertRecentCallImpl(const char* file_name, unsigned int line, const char* function_name)