refactor: clean up imports and add category filter to public song retrieval in SongService

Author: tomast1337

apps/backend/src/song/song.service.ts

@@ -1,27 +1,11 @@
 import { BROWSER_SONGS } from '@nbw/config';
-import { FeaturedSongsDto, TimespanType, UserDocument ,
-  PageQueryDTO,
-  Song as SongEntity,
-  SongPageDto,
-  SongPreviewDto,
-  SongViewDto,
-  SongWithUser,
-  UploadSongDto,
-  UploadSongResponseDto,
-} from '@nbw/database';
-import {
-  HttpException,
-  HttpStatus,
-  Inject,
-  Injectable,
-  Logger,
-} from '@nestjs/common';
+import { FeaturedSongsDto, TimespanType, UserDocument ,  PageQueryDTO,  Song as SongEntity,  SongPageDto,  SongPreviewDto,  SongViewDto,  SongWithUser,  UploadSongDto,  UploadSongResponseDto,} from '@nbw/database';
+import {  HttpException,  HttpStatus,  Inject,  Injectable,  Logger,} from '@nestjs/common';
 import { InjectModel } from '@nestjs/mongoose';
 import { Model } from 'mongoose';
 
 import { FileService } from '@server/file/file.service';
 
-
 import { SongUploadService } from './song-upload/song-upload.service';
 import { SongWebhookService } from './song-webhook/song-webhook.service';
 import { removeExtraSpaces } from './song.util';
@@ -499,6 +483,7 @@ export class SongService {
         {
           $match: {
             visibility: 'public',
+            category  : category,
           },
         },
         {