chore: remove verified dead code paths

src/media-understanding/index.ts

@@ -1,9 +0,0 @@
-export { applyMediaUnderstanding } from "./apply.js";
-export { formatMediaUnderstandingBody } from "./format.js";
-export { resolveMediaUnderstandingScope } from "./scope.js";
-export type {
-  MediaAttachment,
-  MediaUnderstandingOutput,
-  MediaUnderstandingProvider,
-  MediaUnderstandingKind,
-} from "./types.js";