* Ignore Clipper, libpng, mcut and Boost.Polygon Internals in clang-tidy
Each only works through a wrapper or umbrella header: libslic3r/clipper.hpp or clipper_z.hpp configure Clipper before including it, png.h pulls in libpng's config headers, and Boost.Polygon's headers only compile through polygon.hpp or voronoi.hpp.
* Ignore minilzo's Config Headers in clang-tidy
lzoconf.h and lzodefs.h are internal to minilzo.h, which is what the code includes.
* Add Missing Includes Across the Remaining Sources and Tests
Covers src/slic3r/Utils, src/slic3r/plugin, src/slic3r/Config, src/libvgcode, src/dev-utils, src/OrcaSlicer.cpp and tests/, the directories left after src/slic3r/GUI and src/libslic3r. Generated with clang-tidy misc-include-cleaner. libvgcode's own headers are included by relative path as in the rest of that library, and Catch2 and pybind11 with angle brackets as elsewhere in the repo.
* Make the GUI and Test Headers Compile on Their Own
Each now includes, or forward-declares, what it uses instead of relying on what its includers happened to include first. Headers that only compile on one platform, or that nothing built includes, are left alone.
* Keep Windows and nanosvg Setup Ahead of the Added Includes
OrcaSlicer.cpp and several tests set _WIN32_WINNT, WIN32_LEAN_AND_MEAN or NOMINMAX before including Windows.h, and the profile validator defines NANOSVG_IMPLEMENTATION before any libslic3r header. The added includes had landed above those blocks, which broke the Windows build.
* Add the GUI Includes the First Pass Missed
Covers headers that only became editable once they compiled on their own, and wx symbols whose suggested header changed as the clang-tidy ignore list grew after the src/slic3r/GUI pass.
* Keep the Added Test Includes Below the NOMINMAX Guard
test_marchingsquares.cpp and test_texture_displacement.cpp had includes inside #ifndef NOMINMAX, which the tests inherit as defined on Windows from libslic3r, so those were skipped there. .clang-tidy also ignores the MSVC STL and UCRT internals, Boost.Multiprecision's fwd.hpp and CPython's Windows include directory, as in #16068.
The sidebar Mixed Filament list, the extruder icons, the color painting
gizmo and the canvas filament bar now show the same bottom-to-top fade the
Edit Mixed Filament preview shows, custom gradient curves included, instead
of a horizontal fade between the two component colours. Ordinary and vendor
multi-colour filaments are drawn exactly as before.
HanifKoh