Show clear GPU-not-available message instead of stack trace

Add torchvision — required by Gemma4VideoProcessor

Fix build: let HF manage gradio/spaces, remove conflicting deps

Fix: upgrade to gradio 5.x, add pyaudioop, use gr.Tab for 5.x compat

Pin Python 3.11 — fix audioop/pydub incompatibility with Python 3.13

Fix short_description length for HF metadata

Initial Ankahi Space deployment