refactor(build): enhance build_cleaner.py with .gitignore support and auto-discovery

- Added support for .gitignore patterns to the build_cleaner script, allowing it to respect ignored files during maintenance tasks.
- Implemented auto-discovery of CMake libraries marked for auto-maintenance, improving the automation of source list updates.
- Introduced functions for extracting includes and symbols from source files to suggest missing headers based on usage.
- Updated README to reflect new features and usage instructions.

Benefits:
- Streamlines the build process by automating maintenance tasks and ensuring proper header management.
- Enhances code organization and maintainability by integrating with existing project structures.

src/app/gfx/gfx_library.cmake

@@ -75,7 +75,6 @@ message(STATUS "  - GFX Tier: gfx_backend configured")
 set(GFX_RESOURCE_SRC
   app/gfx/resource/arena.cc
   app/gfx/resource/memory_pool.cc
-  app/gfx/render/background_buffer.cc
 )
 add_library(yaze_gfx_resource STATIC ${GFX_RESOURCE_SRC})
 configure_gfx_library(yaze_gfx_resource)
@@ -121,6 +120,7 @@ message(STATUS "  - GFX Tier: gfx_util configured")
 # ==============================================================================
 set(GFX_RENDER_SRC
   app/gfx/render/atlas_renderer.cc
+  app/gfx/render/background_buffer.cc
   app/gfx/render/texture_atlas.cc
   app/gfx/render/tilemap.cc
 )
@@ -174,4 +174,4 @@ if(PNG_FOUND)
   target_link_libraries(yaze_gfx INTERFACE ${PNG_LIBRARIES})
 endif()
 
-message(STATUS "✓ yaze_gfx library configured with tiered architecture")
+message(STATUS "✓ yaze_gfx library configured with tiered architecture")