Add optional GPU flash attention dependencies

README.md

@@ -12,3 +12,13 @@ pinned: false
 # ASL TTS Test
 
 MVP Gradio pour tester la brique TTS, llama.cpp et une interface custom avant de brancher le pipeline vidéo ASL.
+
+## GPU dependencies
+
+`flash-attn` is only useful on a CUDA GPU Space with compatible PyTorch/CUDA versions.
+Keep the default `requirements.txt` for CPU Spaces. If the Space is moved to a compatible
+GPU runtime, install the GPU dependency set instead:
+
+```bash
+pip install -r requirements-gpu.txt --no-build-isolation
+```

requirements-gpu.txt

@@ -0,0 +1,4 @@
+-r requirements.txt
+
+ninja
+flash-attn