Refactor space loading functionality in space_loader_tab.py to streamline the selection and display of popular Hugging Face Spaces. Replace dropdown and button with a dynamic interface that shows the selected space directly, enhancing user experience and code clarity.

Refactor app.py to utilize shared functions for greeting, calculation, and image processing, enhancing modularity and code reuse. Introduce space loading tabs for dynamic integration of popular Hugging Face Spaces.