fix: remove explicit gradio pin, sdk_version controls it

fix: use gr.Tab not gr.TabItem, compatible with Gradio 5.x

fix: bump sdk_version to 5.9.1 (fixes Python 3.13 audioop error)

fix: install phantasm from GitHub source (1.1.0 not yet on PyPI)

fix: lazy model loading + robust error handling in Space app

Add full Gradio demo app

Fix Space card metadata

Add requirements

initial commit