fix(admin): RRO blob switch works for rooms with no RoomScenes row

The seeded Rec Royale rows carry no RoomScenes at all ("Scenes 0"), so the
Sub-rooms tab listed nothing and blob/enable would have 404'd. The admin
list now synthesises the same virtual "Home" entry scene the game-client
details builder does (isVirtual: true, max players = room capacity),
blob/enable creates the real row with the game-side defaults
(RoomsController.GetOrCreateSceneForMutationAsync), and blob/reset copes
with a missing row. Max-players save is disabled on the virtual row.
Test: Room_without_scene_rows_gets_a_virtual_entry_scene_and_enable_creates_it.

DorkNet.Server.Tests/RroRoomBlobTests.cs

@@ -113,6 +113,67 @@ public sealed class RroRoomBlobTests : IClassFixture<DorkNetServerFactory>
         Assert.Equal(string.Empty, SubRoomZero(restored).GetProperty("DataBlob").GetString());
     }
 
+    /// <summary>The seeded Rec Royale rows have NO RoomScenes at all (the admin
+    /// page showed "Scenes 0 / No sub-rooms"). The admin list must synthesise
+    /// the entry scene the way the game-client details do, and enable must
+    /// create the row rather than 404.</summary>
+    [Fact]
+    public async Task Room_without_scene_rows_gets_a_virtual_entry_scene_and_enable_creates_it()
+    {
+        using var setup = Client("rooms");
+        var player = await GameClientSessionFactory.CreateAsync(setup, _factory.ApexDomain);
+        var admin = await GameClientSessionFactory.CreateAsync(setup, _factory.ApexDomain);
+
+        var roomId = 9_670_000 + Random.Shared.Next(1, 99_999);
+        await using (var scope = _factory.Services.CreateAsyncScope())
+        {
+            var db = scope.ServiceProvider.GetRequiredService<DorkNetDbContext>();
+            (await db.Players.FirstAsync(p => p.Id == admin.PlayerId)).IsAdmin = true;
+            db.Rooms.Add(new RoomEntity
+            {
+                Id = roomId,
+                Name = $"NoScene{Guid.NewGuid():N}"[..18],
+                CreatorPlayerId = 1,
+                IsAGRoom = true,
+                TagsCsv = "recroomoriginal",
+                MaxCapacity = 24,
+            });
+            await db.SaveChangesAsync();
+        }
+
+        var synthetic = RoomService.SyntheticDefaultRoomDataBlobName(roomId);
+        using var gameClient = Client("rooms", player);
+        using var adminClient = Client("admin", admin);
+
+        var listed = await GetJsonAsync(adminClient, $"/api/admin/v1/rooms/{roomId}/subrooms");
+        var virtualRow = listed.EnumerateArray().Single();
+        Assert.True(virtualRow.GetProperty("isVirtual").GetBoolean());
+        Assert.Equal(0, virtualRow.GetProperty("subRoomId").GetInt32());
+        Assert.Equal(24, virtualRow.GetProperty("maxPlayers").GetInt32());
+        Assert.Equal(string.Empty, virtualRow.GetProperty("effectiveBlobName").GetString());
+
+        var enabled = await PostJsonAsync(adminClient, $"/api/admin/v1/rooms/{roomId}/subrooms/0/blob/enable");
+        Assert.True(enabled.GetProperty("changed").GetBoolean());
+        Assert.Equal(synthetic, enabled.GetProperty("effectiveBlobName").GetString());
+
+        // The row now exists with the game-side defaults, and the game client
+        // sees the blob on its entry scene.
+        var relisted = await GetJsonAsync(adminClient, $"/api/admin/v1/rooms/{roomId}/subrooms");
+        var real = relisted.EnumerateArray().Single();
+        Assert.False(real.TryGetProperty("isVirtual", out _));
+        Assert.Equal("Home", real.GetProperty("name").GetString());
+        Assert.Equal(24, real.GetProperty("maxPlayers").GetInt32());
+        Assert.Equal(synthetic, real.GetProperty("dataBlobName").GetString());
+
+        var details = await GetJsonAsync(gameClient, $"/rooms/{roomId}");
+        Assert.True(details.GetProperty("IsRRO").GetBoolean());
+        Assert.Equal(synthetic, SubRoomZero(details).GetProperty("DataBlob").GetString());
+
+        var reset = await PostJsonAsync(adminClient, $"/api/admin/v1/rooms/{roomId}/subrooms/0/blob/reset");
+        Assert.True(reset.GetProperty("changed").GetBoolean());
+        Assert.Equal(string.Empty, SubRoomZero(await GetJsonAsync(gameClient, $"/rooms/{roomId}")).GetProperty("DataBlob").GetString());
+    }
+
     [Fact]
     public async Task Enable_on_a_saved_subroom_keeps_the_saved_blob()
     {

DorkNet.Server/Controllers/Admin/AdminController.cs

@@ -1120,6 +1120,33 @@ public class AdminController(
         var room = await db.Rooms.AsNoTracking().FirstAsync(r => r.Id == id);
         var bakedOriginal = RoomService.IsBakedOriginalRoom(room);
 
+        // Seeded baked originals (Rec Royale, …) have NO RoomScenes rows at
+        // all; the game-client details builder synthesises a "Home" entry
+        // scene for them (RoomsController.BuildSubRoomWire with a null scene)
+        // and the mutation handlers create the row on first write. Mirror
+        // that here so the SPA has something to act on — the blob/enable
+        // action below creates the real row.
+        if (scenes.Count == 0)
+        {
+            return Ok(new[]
+            {
+                new
+                {
+                    id = "0",
+                    subRoomId = 0,
+                    name = "Home",
+                    maxPlayers = room.MaxCapacity,
+                    canMatchmakeInto = true,
+                    isSandbox = false,
+                    dataBlobName = string.Empty,
+                    effectiveBlobName = EffectiveSubRoomBlobName(room, null, bakedOriginal),
+                    isBakedOriginal = bakedOriginal,
+                    isVirtual = true,
+                    dataModifiedAt = room.UpdatedAt,
+                },
+            });
+        }
+
         return Ok(scenes.Select(s => new
         {
             // Ids go out as strings: the admin SPA is JavaScript and silently
@@ -1142,9 +1169,9 @@ public class AdminController(
         }).ToList());
     }
 
-    private static string EffectiveSubRoomBlobName(RoomEntity room, RoomSceneEntity scene, bool bakedOriginal)
+    private static string EffectiveSubRoomBlobName(RoomEntity room, RoomSceneEntity? scene, bool bakedOriginal)
     {
-        if (!string.IsNullOrWhiteSpace(scene.DataBlobName)) return scene.DataBlobName;
+        if (!string.IsNullOrWhiteSpace(scene?.DataBlobName)) return scene!.DataBlobName;
         if (!string.IsNullOrWhiteSpace(room.CurrentDataBlobName)) return room.CurrentDataBlobName;
         if (bakedOriginal) return string.Empty;
         return RoomService.SyntheticDefaultRoomDataBlobName(room.Id);
@@ -1183,14 +1210,31 @@ public class AdminController(
         var room = await db.Rooms.FirstOrDefaultAsync(r => r.Id == id);
         if (room is null) return NotFound();
         var scene = await db.RoomScenes.FirstOrDefaultAsync(s => s.RoomId == id && s.OrderIndex == subRoomId);
-        if (scene is null) return NotFound();
+        if (scene is null && subRoomId != 0) return NotFound();
 
         var bakedOriginal = RoomService.IsBakedOriginalRoom(room);
-        if (!string.IsNullOrWhiteSpace(scene.DataBlobName))
+        if (scene is not null && !string.IsNullOrWhiteSpace(scene.DataBlobName))
             return Ok(SubRoomBlobWire(room, scene, bakedOriginal, changed: false));
 
         var blobName = SyntheticSubRoomBlobName(id, subRoomId);
         var now = DateTime.UtcNow;
+        if (scene is null)
+        {
+            // Seeded baked originals carry no RoomScenes row; create the
+            // entry scene with the same defaults the game-side mutation
+            // path uses (RoomsController.GetOrCreateSceneForMutationAsync).
+            scene = new RoomSceneEntity
+            {
+                RoomId = room.Id,
+                OrderIndex = 0,
+                Name = "Home",
+                RoomSceneLocationId = room.LocationReplicationId,
+                MaxPlayers = room.MaxCapacity,
+                IsSandbox = false,
+                CanMatchmakeInto = true,
+            };
+            db.RoomScenes.Add(scene);
+        }
         scene.DataBlobName = blobName;
         scene.DataModifiedAt = now;
         if (subRoomId == 0 && string.IsNullOrWhiteSpace(room.CurrentDataBlobName))
@@ -1217,15 +1261,15 @@ public class AdminController(
         var room = await db.Rooms.FirstOrDefaultAsync(r => r.Id == id);
         if (room is null) return NotFound();
         var scene = await db.RoomScenes.FirstOrDefaultAsync(s => s.RoomId == id && s.OrderIndex == subRoomId);
-        if (scene is null) return NotFound();
+        if (scene is null && subRoomId != 0) return NotFound();
 
         var bakedOriginal = RoomService.IsBakedOriginalRoom(room);
-        var previousScene = scene.DataBlobName;
+        var previousScene = scene?.DataBlobName ?? string.Empty;
         var previousRoom = room.CurrentDataBlobName;
         var changed = false;
         var now = DateTime.UtcNow;
 
-        if (!string.IsNullOrWhiteSpace(scene.DataBlobName))
+        if (scene is not null && !string.IsNullOrWhiteSpace(scene.DataBlobName))
         {
             scene.DataBlobName = string.Empty;
             scene.DataModifiedAt = now;
@@ -1247,12 +1291,12 @@ public class AdminController(
         return Ok(SubRoomBlobWire(room, scene, bakedOriginal, changed));
     }
 
-    private static object SubRoomBlobWire(RoomEntity room, RoomSceneEntity scene, bool bakedOriginal, bool changed) => new
+    private static object SubRoomBlobWire(RoomEntity room, RoomSceneEntity? scene, bool bakedOriginal, bool changed) => new
     {
-        id = scene.Id.ToString(),
+        id = (scene?.Id ?? 0).ToString(),
-        subRoomId = scene.OrderIndex,
+        subRoomId = scene?.OrderIndex ?? 0,
-        name = scene.Name,
+        name = scene?.Name ?? "Home",
-        dataBlobName = scene.DataBlobName,
+        dataBlobName = scene?.DataBlobName ?? string.Empty,
         roomCurrentDataBlobName = room.CurrentDataBlobName,
         effectiveBlobName = EffectiveSubRoomBlobName(room, scene, bakedOriginal),
         isBakedOriginal = bakedOriginal,

DorkNet.Server/admin-ui/src/pages/Room.tsx

@@ -568,6 +568,9 @@ interface SubRoom {
    *  with no blob enabled (scene geometry only, no Maker Pen / chips). */
   effectiveBlobName: string;
   isBakedOriginal: boolean;
+  /** No RoomScenes row exists yet (seeded baked originals); the entry
+   *  scene is synthesised on read and created by "Enable Maker Pen blob". */
+  isVirtual?: boolean;
 }
 
 // Per-sub-room player caps. Distinct from the room's own MaxCapacity, which is
@@ -718,8 +721,9 @@ function SubRoomsTab({ roomId, roomCapacity }: { roomId: number; roomCapacity: n
                   />
                   <button
                     onClick={() => save(sub)}
-                    disabled={!dirty || saving === sub.subRoomId}
+                    disabled={!dirty || saving === sub.subRoomId || sub.isVirtual}
                     className="btn-primary text-xs"
+                    title={sub.isVirtual ? 'This room has no sub-room row yet — enable the blob first' : undefined}
                   >
                     {saving === sub.subRoomId ? 'Saving…' : 'Save'}
                   </button>

docs/admin.md

@@ -208,7 +208,11 @@ actions:
   room roles, no objects) while nothing is saved. `IsRRO` is derived from
   `IsAGRoom`, so the client keeps loading the baked map and only
   additionally fetches the blob. Idempotent; a no-op on a sub-room that
-  already has a blob.
+  already has a blob. Seeded originals such as Rec Royale have **no
+  `RoomScenes` row at all** ("Scenes 0"); the list synthesises a virtual
+  "Home" entry (`isVirtual: true`, max players = room capacity) and enable
+  creates the real row with the game-side defaults
+  (`RoomsController.GetOrCreateSceneForMutationAsync`).
 - **Reset to baked scene** — `POST api/admin/v1/rooms/{id}/subrooms/{subRoomId}/blob/reset`.
   Clears both pointers. This is the escape hatch if a save left the room
   unplayable. Saved blobs stay in `RoomDataBlobs`, so the in-game restore