Update public exports and README for Client class

Exports Client, all lower-level modules, and all types from
src/index.ts. Replaces Phase 7 (on-disk session persistence) with
the Client class phase: session lives in the object, consumer
handles persistence via toJSON/fromJSON.

src/index.ts

@@ -1,9 +1,31 @@
 export const VERSION = "0.0.0";
 
+export { Client, type LoginOptions, type ClientSnapshot } from "./client.js";
+export { ApiClient, ApiError, type ApiClientOptions } from "./api/client.js";
 export { unwrapAuth, type UnwrapResult } from "./auth/unwrap.js";
+export {
+    beginLogin,
+    submitTOTP,
+    requestEmailOTP,
+    submitEmailOTP,
+} from "./auth/login.js";
+export { decryptCollection, decryptFile } from "./model/index.js";
+export { downloadFile, downloadThumbnail } from "./download/index.js";
 export type {
     AuthorizationResponse,
     KeyAttributes,
     LoginChallenge,
     SRPAttributes,
 } from "./auth/types.js";
+export type {
+    Collection,
+    CollectionType,
+    EnteFile,
+    FileBlob,
+    FileMetadata,
+    FileType,
+    Microseconds,
+    RawCollection,
+    RawEnteFile,
+} from "./model/types.js";
+export type { DownloadResult } from "./download/index.js";