Enhance global friends functionality: suppress auto-generated placeholder accounts in synthesized friend lists and update documentation for clarity.

DorkNet.Server/Services/RelationshipQueries.cs

@@ -31,9 +31,30 @@ public static class RelationshipQueries
     /// friend in anyone's list.</summary>
     public const long SystemAccountId = 1;
 
+    /// <summary>True when <paramref name="username"/> is still an
+    /// auto-generated placeholder name (<c>Player_</c> followed by digits
+    /// only — see <c>PlayerService.GenerateUsername</c>). These are accounts
+    /// that never set a real username; the global-friends toggle hides them
+    /// from the synthesized "everyone" list so they don't clutter it. A
+    /// genuine Friend row still surfaces them — only the synthetic pairing is
+    /// suppressed.</summary>
+    public static bool IsPlaceholderUsername(string? username)
+    {
+        const string prefix = "Player_";
+        if (string.IsNullOrEmpty(username) ||
+            !username.StartsWith(prefix, StringComparison.Ordinal)) return false;
+        var suffix = username.AsSpan(prefix.Length);
+        if (suffix.IsEmpty) return false;
+        foreach (var c in suffix)
+            if (!char.IsAsciiDigit(c)) return false;
+        return true;
+    }
+
     /// <summary>The effective friend ids for <paramref name="me"/>. With the
     /// global-friends toggle off this is the real Friend graph; with it on
-    /// it's every other (non-system, non-blocked) account.</summary>
+    /// it's every other (non-system, non-blocked) account, excluding
+    /// placeholder <c>Player_NNN</c> accounts that aren't already real
+    /// friends.</summary>
     public static async Task<List<long>> EffectiveFriendIdsAsync(
         DorkNetDbContext db, ServerSettingsService settings, long me)
     {
@@ -53,10 +74,21 @@ public static class RelationshipQueries
                         (r.RequesterId == me || r.TargetId == me))
             .Select(r => r.RequesterId == me ? r.TargetId : r.RequesterId)
             .ToListAsync();
+        var realFriendSet = (await db.Relationships
+            .Where(r => r.Status == RelationshipStatus.Friend &&
+                        (r.RequesterId == me || r.TargetId == me))
+            .Select(r => r.RequesterId == me ? r.TargetId : r.RequesterId)
+            .ToListAsync()).ToHashSet();
 
-        return await db.Players
+        var candidates = await db.Players
             .Where(p => p.Id != me && p.Id != SystemAccountId && !blocked.Contains(p.Id))
-            .Select(p => p.Id)
+            .Select(p => new { p.Id, p.Username })
             .ToListAsync();
+
+        // Suppress placeholder accounts unless they're an actual friend.
+        return candidates
+            .Where(p => realFriendSet.Contains(p.Id) || !IsPlaceholderUsername(p.Username))
+            .Select(p => p.Id)
+            .ToList();
     }
 }