Make it more complete

Database.cs

@@ -22,7 +22,7 @@ namespace Tesses.YouTubeDownloader2025Companion
 
         public void Init()
         {
-            conn.Execute("CREATE TABLE IF NOT EXISTS sessions (Id INTEGER PRIMARY KEY AUTOINCREMENT, AccountName TEXT, Key TEXT UNIQUE, Expires INTEGER);");
+            conn.Execute("CREATE TABLE IF NOT EXISTS sessions (Id INTEGER PRIMARY KEY AUTOINCREMENT, AccountName TEXT, Key TEXT UNIQUE, Expires INTEGER, Flags INTEGER);");
             conn.Execute("CREATE TABLE IF NOT EXISTS song_videos (Id INTEGER PRIMARY KEY AUTOINCREMENT, SongId TEXT UNIQUE, VideoId TEXT UNIQUE, VideoTitle TEXT);");
             conn.Execute("CREATE TABLE IF NOT EXISTS songs (Id INTEGER PRIMARY KEY AUTOINCREMENT, SongId TEXT UNIQUE, SongName TEXT);");
             conn.Execute("CREATE TABLE IF NOT EXISTS artists (Id INTEGER PRIMARY KEY AUTOINCREMENT, ArtistId TEXT UNIQUE, ArtistName TEXT, ArtistDisambiguation TEXT);");
@@ -87,14 +87,15 @@ namespace Tesses.YouTubeDownloader2025Companion
                 yield return ent;
             }
         }
-        public async Task<Session> CreateSessionTokenAsync(string username, bool expires = true)
+        public async Task<Session> CreateSessionTokenAsync(string username, long flags, bool expires = true)
         {
             Session session = new Session();
             session.AccountName = username;
             session.Expires = expires ? Program.NowEpoch + Expires : 0;
+            session.Flags = flags;
             session.Key = Convert.ToBase64String(RandomNumberGenerator.GetBytes(32));
 
-            await conn.ExecuteAsync("INSERT INTO sessions (AccountName,Key,Expires) VALUES (@AccountName,@Key,@Expires);", session);
+            await conn.ExecuteAsync("INSERT INTO sessions (AccountName,Key,Flags,Expires) VALUES (@AccountName,@Key,@Flags,@Expires);", session);
 
             return session;
         }
@@ -226,6 +227,16 @@ namespace Tesses.YouTubeDownloader2025Companion
                 ArtistId = artistId
             }));
         }
+        public async Task<IEnumerable<Song>> GetUnavailableSongsAsync(long offset=0, long count=20)
+        {
+            //SELECT * FROM songs s WHERE NOT EXISTS (SELECT * FROM song_videos v WHERE v.SongId = s.SongId);
+            return await conn.QueryAsync<Song>("SELECT * FROM songs s WHERE NOT EXISTS (SELECT * FROM song_videos v WHERE v.SongId = s.SongId) LIMIT @Count OFFSET @Offset;", new DynamicParameters(new
+            {
+                Offset = offset,
+                Count = count
+            }));
+        }
+
         public async Task<IEnumerable<Album>> GetAlbumsAsync(string q = "", long offset = 0, long count = 20)
         {
             return await conn.QueryAsync<Album>("SELECT * FROM albums WHERE AlbumName LIKE @Query ORDER BY AlbumReleaseDate, Id ASC LIMIT @Count OFFSET @Offset;", new DynamicParameters(new
@@ -323,6 +334,8 @@ namespace Tesses.YouTubeDownloader2025Companion
 
             public string Key { get; set; } = "";
 
+            public long Flags {get;set;}
+
             public long Expires { get; set; }
         }
     }