Scaffold the n3xd-ocp binding repo

Placeholder for the hand-written nanobind bindings over OCCT (roadmap Phase 10
in the app repo). Carries the gitignore for a scikit-build-core/CMake
extension plus the OCCT build trees, and keeps .secrets — the Gitea publish
PAT — out of history.

.gitignore

@@ -0,0 +1,36 @@
+# Credentials (the Gitea publish PAT lives here)
+.secrets
+
+# Python
+__pycache__/
+*.py[cod]
+.venv/
+venv/
+*.egg-info/
+.pytest_cache/
+.ruff_cache/
+
+# Build output — scikit-build-core drives CMake into these
+build/
+_skbuild/
+dist/
+wheelhouse/
+CMakeUserPresets.json
+
+# Compiled extension / generated stubs land in the package tree
+*.so
+*.dylib
+*.pyd
+python/OCP/*.pyi
+
+# Vendored or locally built OCCT (never committed; it comes from the
+# builder image, and a kernel tree would dwarf this repo)
+occt/build/
+occt/install/
+third_party/
+
+# Editor / OS
+.vscode/*
+!.vscode/extensions.json
+.idea/
+.DS_Store