Update README.md with additional installation instructions for CPU-only PyTorch

README.md

@@ -58,11 +58,18 @@ Manual startup:
 
 ```bash
 python3.13 -m venv backend/.venv
+backend/.venv/bin/python -m pip install --upgrade pip
 backend/.venv/bin/python -m pip install -r backend/requirements.txt
 npm install
 npm run dev
 ```
 
+On Steam Deck / SteamOS, or any non-NVIDIA Linux host where you want Whisper on CPU, install CPU-only PyTorch first:
+
+```bash
+backend/.venv/bin/python -m pip install --index-url https://download.pytorch.org/whl/cpu torch
+```
+
 ## Project Layout
 
 ```text