/**
 * Microsoft Graph's `?format=pdf` / `?format=html` conversion accepts a
 * fixed set of source extensions. For anything outside that whitelist
 * Graph (or its downstream Office Online sandbox) returns a 4xx, which
 * is a cryptic failure mode for an LLM agent.
 *
 * The conversion commands short-circuit on the extensions below and
 * return the raw bytes instead of attempting (and wasting) a Graph
 * round-trip:
 *
 *   - PLAIN_TEXT_EXTENSIONS: extensions that are themselves plain text
 *     (txt/md/json/yaml/etc.) — turning these through `?format=pdf` or
 *     `?format=html` is meaningless; just return the bytes.
 *
 *   - `pdf`: the `*-as-pdf` commands ask Graph to convert TO pdf, but
 *     `pdf` is NOT in Graph's `format=pdf` source-input list (verified
 *     2026-05 against svc.ms; CDN responds 406 InputFormatNotSupported).
 *     The user wanted a PDF and the source IS a PDF, so return its
 *     bytes directly.
 */
declare const PLAIN_TEXT_EXTENSIONS: ReadonlySet<string>;
declare const isPlainTextFilename: (name: string) => boolean;
declare const isPdfSource: (name: string) => boolean;
export { isPdfSource, isPlainTextFilename, PLAIN_TEXT_EXTENSIONS };