debug_ui.h (50→10 lines): GUI_ERROR/WARN/INFO/DEBUG now delegate to DEBUG_ERROR/WARN/INFO/DEBUG(DEBUG_CATEGORY_DEBUG, ...) from debug_config.h Eliminates dual logging output, dual log file configuration. Removed guiDebugFile() — debug_enable_file_output() already handles it. Removed debug_ui.h include from utun_node.cpp (unused).