Add brew_entrypoint.sh

brew_entrypoint.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+# Installs Homebrew into the mounted volume the first time the container starts,
+# then hands off to the normal OpenClaw command.
+set -e
+
+BREW_PREFIX=/home/linuxbrew/.linuxbrew
+
+if [ ! -x "$BREW_PREFIX/bin/brew" ]; then
+    echo "[brew] First start: installing Homebrew into $BREW_PREFIX"
+    mkdir -p "$BREW_PREFIX/bin"
+    git clone --depth=1 https://github.com/Homebrew/brew "$BREW_PREFIX/Homebrew"
+    ln -sf ../Homebrew/bin/brew "$BREW_PREFIX/bin/brew"
+    "$BREW_PREFIX/bin/brew" update --force --quiet
+    echo "[brew] Done."
+fi
+
+exec "$@"