Make this fork actually compile: first green Catch2 run in its history

206/206 targets built, 139 [CadDocument] cases / 1960 assertions passing —
identical to snaporca's suite. Until now this fork had never compiled at all:
CMake died at configure, so the M1-M8 "suite green" figures were snaporca's
alone and the ports rested on patch-apply plus byte-identical sources.

Three fixes here; the deps work is in the orcacad-deps image (see below).

1. kernel-test.sh mounts deps_src. pybind11 is vendored in-tree and CMakeLists
   requires its headers; without the mount the container fell back to the
   image's baked tree, which predates it.

2. tests/libslic3r/test_3mf.cpp: repair the upstream-merge conflict resolution.
   Resolving it as a union dropped the three closing braces of our SCENARIO, so
   upstream's SCENARIO opened inside ours ("a function-definition is not allowed
   here", plus 12 cascading catch2 registry errors). Restored from the pre-merge
   file; whole-file brace balance is now 0 and the case count reconciles as
   5 (ours) + 8 (upstream) - 3 (shared) = 10, with both CAD recipe tests intact.

3. tests/libslic3r/test_caddocument.cpp: REQUIRE_CONTAINS / CHECK_CONTAINS.
   Catch2 v2 (snaporca) spells substring-match Matchers::Contains; v3 (here)
   spells it ContainsSubstring and gives Contains an incompatible meaning,
   range-contains-ELEMENT, which fails to COMPILE against std::string. Four
   sites had been hand-adapted long ago, but M2-M8 kept porting in un-adapted
   Contains calls — 16 of them — and nothing objected because nothing compiled.
   Both forks now use the same find()-based macros, so the assertion lines are
   byte-identical again and future format-patch ports carry across unchanged.
   Five orphaned `using Catch::Matchers::Contains;` lines removed with them.

The deps gap that blocked configure needed five additions on top of
snaporca-deps, built into image orcacad-deps: Eigen 5.0.1, Python 3.12.13
(exact, with Development.Embed), wxWidgets 3.3.2 (was 3.1.5), CGAL 5.6.3
(was 5.4 — mainline's own MeshBoolean.cpp calls CGAL::parameters::default_values,
added in 5.5), plus the pybind11 mount above. OCCT V7_6_0, Boost 1.84.0 and
OpenCV 4.6.0 are pinned identically in both forks and were reused as-is.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

scripts/kernel-test.sh

@@ -85,6 +85,7 @@ docker run --rm \
   -v "$REPO/resources":/OrcaSlicer/resources \
   -v "$REPO/CMakeLists.txt":/OrcaSlicer/CMakeLists.txt \
   -v "$REPO/cmake":/OrcaSlicer/cmake \
+  -v "$REPO/deps_src":/OrcaSlicer/deps_src \
   -v "$VOL":/OrcaSlicer/build \
   "$IMAGE" \
   bash -lc "set -e