test: add beta tag install option for docker installer

scripts/test-install-sh-e2e-docker.sh

@@ -19,6 +19,7 @@ docker build \
 echo "==> Run E2E installer test"
 docker run --rm -t \
   -e CLAWDBOT_INSTALL_URL="$INSTALL_URL" \
+  -e CLAWDBOT_INSTALL_TAG="${CLAWDBOT_INSTALL_TAG:-latest}" \
   -e CLAWDBOT_E2E_MODELS="$CLAWDBOT_E2E_MODELS" \
   -e CLAWDBOT_INSTALL_E2E_PREVIOUS="${CLAWDBOT_INSTALL_E2E_PREVIOUS:-}" \
   -e CLAWDBOT_INSTALL_E2E_SKIP_PREVIOUS="${CLAWDBOT_INSTALL_E2E_SKIP_PREVIOUS:-0}" \