fix: add uv install path in speedrun script

runs/speedrun.sh

@@ -20,6 +20,8 @@ mkdir -p $NANOCHAT_BASE_DIR
 
 # install uv (if not already installed)
 command -v uv &> /dev/null || curl -LsSf https://astral.sh/uv/install.sh | sh
+# add uv to PATH for shells that don't auto-pick up ~/.local/bin after install
+export PATH="$HOME/.local/bin:$PATH"
 # create a .venv local virtual environment (if it doesn't exist)
 [ -d ".venv" ] || uv venv
 # install the repo dependencies