refactor: unify inline directives and media fetch

src/media/audio.ts

@@ -0,0 +1,18 @@
+import { getFileExtension } from "./mime.js";
+
+const VOICE_AUDIO_EXTENSIONS = new Set([".oga", ".ogg", ".opus"]);
+
+export function isVoiceCompatibleAudio(opts: {
+  contentType?: string | null;
+  fileName?: string | null;
+}): boolean {
+  const mime = opts.contentType?.toLowerCase();
+  if (mime && (mime.includes("ogg") || mime.includes("opus"))) {
+    return true;
+  }
+  const fileName = opts.fileName?.trim();
+  if (!fileName) return false;
+  const ext = getFileExtension(fileName);
+  if (!ext) return false;
+  return VOICE_AUDIO_EXTENSIONS.has(ext);
+}