A login's storage is counted, and can have a quota

MediaAttachment.Size was stored and never summed: nobody, the administrator included, could tell what media took,
and nothing bounded it. Counted.Media and MediaOfRoot sum what is kept (not trashed). A login sees what its personas'
uploads and pictures take at /clientapi/user/storage (ViewStorage), with its quota when the server sets one;
Media:QuotaBytesPerRoot (0, no quota, by default) refuses an upload or a picture over it with 422, whichever persona
sends it; the statistics overview gains the media totals, the proxy cache and the trash (ViewMediaTotals). Tests: a
login's storage counts what its personas keep and forgets what is trashed; two uploads from two personas of one login
are refused together past the quota.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

PrivaPub/Domain/Privacy/Counted.cs

@@ -1,3 +1,4 @@
+using MongoDB.Driver;
 using MongoDB.Entities;
 
 using PrivaPub.Federation.Actors;
@@ -64,6 +65,24 @@ namespace PrivaPub.Domain.Privacy
 			return distinct.Count == 0 ? 0 : await DB.Default.CountAsync<Avatar>(a => distinct.Contains(a.ID) && !a.DeletionAt.HasValue, token);
 		}
 
+		// the media kept (not trashed) that which holds: their bytes and how many
+		public static async Task<(long Bytes, long Files)> Media(Expression<Func<Models.Media.MediaAttachment, bool>> which, CancellationToken token)
+		{
+			var totals = await DB.Default.Fluent<Models.Media.MediaAttachment>()
+				.Match(m => m.TrashedAt == null)
+				.Match(which)
+				.Group(m => true, g => new { Bytes = g.Sum(m => m.Size), Files = g.LongCount() })
+				.FirstOrDefaultAsync(token);
+			return totals == default ? (0, 0) : (totals.Bytes, totals.Files);
+		}
+
+		// a login's media: every persona's uploads and pictures
+		public static async Task<(long Bytes, long Files)> MediaOfRoot(string rootId, CancellationToken token)
+		{
+			var personas = (await DB.Default.Find<Models.User.RootToAvatar>().Match(r => r.RootId == rootId).ExecuteAsync(token)).Select(r => r.AvatarId).ToList();
+			return await Media(m => personas.Contains(m.OwnerAvatarId), token);
+		}
+
 		public static async Task<long> LocalPosts(CancellationToken token)
 		{
 			var barred = await BarredPersonas(token);