Initial production-ready Gemma 3 vLLM ROCm stack

Co-Authored-By: Oz <oz-agent@warp.dev>

scripts/test_ui.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+# Tests whether the chat UI is reachable on localhost frontend port.
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+REPO_ROOT="$(cd "${SCRIPT_DIR}/.." && pwd)"
+ENV_FILE="${REPO_ROOT}/.env"
+
+if [[ -f "${ENV_FILE}" ]]; then
+  # shellcheck disable=SC1090
+  source "${ENV_FILE}"
+fi
+
+FRONTEND_PORT="${FRONTEND_PORT:-3000}"
+UI_URL="http://localhost:${FRONTEND_PORT}"
+
+http_status="$(curl -sS -o /dev/null -w '%{http_code}' "${UI_URL}")"
+
+if [[ "${http_status}" != "200" && "${http_status}" != "301" && "${http_status}" != "302" ]]; then
+  echo "[test_ui][error] UI check failed with HTTP status ${http_status} at ${UI_URL}" >&2
+  echo "[test_ui][hint] See docs/TROUBLESHOOTING.md#ui-loads-but-cannot-reach-vllm-backend" >&2
+  exit 1
+fi
+
+echo "[test_ui] Chat UI is reachable at ${UI_URL} (HTTP ${http_status})."