fix(release): validate remote business response codes

scripts/release-preflight.sh

@@ -72,6 +72,17 @@ require_fresh_artifact "$mobile_index"
 require_fresh_artifact "$mobile_asset_path"
 require_fresh_artifact "$backend_jar"
 
+require_remote_business_success() {
+  local label="$1"
+  local url="$2"
+  local body
+  body="$(curl -fsS --max-time 15 "$url")" || fail "$label HTTP check failed: $url"
+  if ! printf '%s' "$body" | LC_ALL=C grep -Eq '"code"[[:space:]]*:[[:space:]]*200([[:space:]]*[,}])'; then
+    fail "$label business check failed: $url"
+  fi
+  echo "$label=200 $url"
+}
+
 changed_files="$(git status --porcelain)"
 [[ -z "$changed_files" ]] || fail "worktree has uncommitted changes; commit the release batch before publishing"
 
@@ -90,11 +101,7 @@ if [[ -n "${RELEASE_REMOTE_URL:-}" ]]; then
   remote="${RELEASE_REMOTE_URL%/}"
   curl -fsS --max-time 15 "$remote/" >/dev/null || fail "remote root check failed: $remote/"
   echo "remote_root=200 $remote/"
-  if curl -fsS --max-time 15 "$remote/prod-api/auth/tenant/list" >/dev/null; then
-    echo "remote_tenant_list=200 $remote/prod-api/auth/tenant/list"
-  else
-    fail "remote tenant list check failed: $remote/prod-api/auth/tenant/list"
-  fi
+  require_remote_business_success "remote_tenant_list" "$remote/prod-api/auth/tenant/list"
 
   if [[ "${RELEASE_VERIFY_REMOTE_MATCH:-false}" == "true" ]]; then
     remote_frontend_asset="$(curl -fsS --max-time 15 "$remote/" | sed -nE 's/.*src="(\/assets\/[^" ]+\.js)".*/\1/p' | head -n 1)"