Set up CMAKE for Linux and Windows.

.gitignore

@@ -0,0 +1,54 @@
+# ------------------------
+# Build artifacts
+# ------------------------
+/build/
+/CMakeFiles/
+/CMakeCache.txt
+/Makefile
+/*.ninja
+/.ninja_deps
+/.ninja_log
+/*.sln
+/*.vcxproj*
+/compile_commands.json
+/install_manifest.txt
+
+# ------------------------
+# Binary outputs
+# ------------------------
+/*.exe
+/*.dll
+/*.so
+/*.dylib
+/*.a
+/*.lib
+/*.obj
+/*.o
+/*.pdb
+
+# ------------------------
+# OS / editor junk
+# ------------------------
+.DS_Store
+Thumbs.db
+*.swp
+*.swo
+*.user
+*.VC.db
+*.idea/
+*.vscode/
+*.vs/
+
+# ------------------------
+# Logs / temp
+# ------------------------
+*.log
+*.tmp
+
+# ------------------------
+# Python venv (if you use scripts/tools)
+/venv/
+
+# ------------------------
+# Keep empty asset dirs if needed
+assets/**/.gitkeep