Update build environment to Alpine, enable GUI support, and refine developer guide
- Migrated Dockerfile base image from Ubuntu 22.04 to Alpine 3.19 for a smaller and faster container.
- Added dependencies for GUI support (SDL2, OpenGL/Mesa, Freetype, etc.) and updated CMake options.
- Enhanced `DEVELOPER_GUIDE.md` with new instructions for GUI builds, updated dependencies, and simplified custom build workflows.
- Addressed Alpine-specific ncurses library path issues in CMake configuration.
Kyle Isom
b0b5b55dce
