refactor: add gateway server helper modules

src/gateway/server-utils.ts

@@ -0,0 +1,34 @@
+import { defaultVoiceWakeTriggers } from "../infra/voicewake.js";
+
+export function normalizeVoiceWakeTriggers(input: unknown): string[] {
+  const raw = Array.isArray(input) ? input : [];
+  const cleaned = raw
+    .map((v) => (typeof v === "string" ? v.trim() : ""))
+    .filter((v) => v.length > 0)
+    .slice(0, 32)
+    .map((v) => v.slice(0, 64));
+  return cleaned.length > 0 ? cleaned : defaultVoiceWakeTriggers();
+}
+
+export function formatError(err: unknown): string {
+  if (err instanceof Error) return err.message;
+  if (typeof err === "string") return err;
+  const statusValue = (err as { status?: unknown })?.status;
+  const codeValue = (err as { code?: unknown })?.code;
+  const statusText =
+    typeof statusValue === "string" || typeof statusValue === "number"
+      ? String(statusValue)
+      : undefined;
+  const codeText =
+    typeof codeValue === "string" || typeof codeValue === "number"
+      ? String(codeValue)
+      : undefined;
+  if (statusText || codeText) {
+    return [statusText, codeText].filter(Boolean).join(" ");
+  }
+  try {
+    return JSON.stringify(err, null, 2);
+  } catch {
+    return String(err);
+  }
+}