Refactor project structure and remove unnecessary files

- Deleted generated CMake files and build artifacts from the cmake-build-debug directory.
- Removed the Intellisense header - what was that???
- Cleaned up the melonDS.ini configuration (removed hard path)

.gitignore

@@ -46,6 +46,23 @@
 *.x86_64
 *.hex
 
+# CMake/Ninja build outputs
+/build/
+/build-debug/
+/cmake-build-*/
+/compile_commands.json
+
+# CMake internals
+CMakeCache.txt
+cmake_install.cmake
+build.ninja
+.ninja_deps
+.ninja_log
+CMakeFiles/
+
+# Generated build artifacts
+*.lst
+
 # Debug files
 *.dSYM/
 *.su
@@ -59,4 +76,7 @@
 modules.order
 Module.symvers
 Mkfile.old
-dkms.conf
+dkms.conf
+
+# MelonDS config
+melonDS.ini