interceptManifestRequest

Optional hook to inspect/modify the manifest HTTP request before the SDK fetches it (initial fetch and every poll). Can redirect the URL, add headers, or short-circuit the network with a mocked raw body (parsed + validated normally). May suspend. On throw emits DA-MANIFEST-REQUEST-INTERCEPT-FAILED and falls back to the normal network fetch. See ManifestRequestInterceptor. The SDK forwards it to the ManifestSource; the default HttpManifestSource applies it.