feat(quick-001): regenerate bindings and update frontend for multi-import

- Wails bindings reflect new PlaylistFilePicker and ImportPlaylists signatures
- Frontend handleImportPlaylist now passes file array to ImportPlaylists

frontend/wailsjs/go/frontendutil/FrontendUtil.d.ts

@@ -4,6 +4,6 @@ import {context} from '../models';
 
 export function DirectoryPicker():Promise<string>;
 
-export function PlaylistFilePicker():Promise<string>;
+export function PlaylistFilePicker():Promise<Array<string>>;
 
 export function SetContext(arg1:context.Context):Promise<void>;

frontend/wailsjs/go/playlist/Service.d.ts

@@ -31,6 +31,8 @@ export function GetPlaylistTracks(arg1:number):Promise<Array<playlist.Track>>;
 
 export function ImportPlaylist(arg1:string):Promise<playlist.Summary>;
 
+export function ImportPlaylists(arg1:Array<string>):Promise<Array<playlist.Summary>>;
+
 export function RemoveFromDefaultPlaylist(arg1:Array<string>):Promise<void>;
 
 export function RemovePhantomTracks(arg1:number,arg2:Array<string>):Promise<void>;

frontend/wailsjs/go/playlist/Service.js

@@ -58,6 +58,10 @@ export function ImportPlaylist(arg1) {
   return window['go']['playlist']['Service']['ImportPlaylist'](arg1);
 }
 
+export function ImportPlaylists(arg1) {
+  return window['go']['playlist']['Service']['ImportPlaylists'](arg1);
+}
+
 export function RemoveFromDefaultPlaylist(arg1) {
   return window['go']['playlist']['Service']['RemoveFromDefaultPlaylist'](arg1);
 }