fix: sub-room id sequence, restore sync, presence index TTL, permission races

From the local CodeRabbit review:
- Scene ids: the repair and room clone assigned max + 1, which never
  advanced the Postgres identity sequence (live: sequence 3412, max id 3466),
  so the next add / clone sub-room would collide on the primary key. The
  repair now moves the sequence past the highest id at startup, and both
  let the database assign ids.
- Room-level restores (datahistory/restore and the admin restore) now also
  restore the entry sub-room, whose blob room details serve first.
- TouchRoom refreshes the room's presence index too, so players kept alive
  only by heartbeats no longer drop out of the instance browser after 20 min.
- Sub-room permission saves match cells exactly (as the unique index does)
  and retry when a concurrent editor inserted the same new cell.

DorkNet.Server.Tests/SubRoomsAndInstances2023Tests.cs

@@ -118,6 +118,35 @@ public sealed class SubRoomsAndInstances2023Tests : IClassFixture<DorkNetServerF
         Assert.Equal((0, 0), await service.RepairRoomScenesAsync());
     }
 
+    [Fact]
+    public async Task Room_level_restore_also_restores_the_entry_sub_room()
+    {
+        var owner = await PlayerAsync();
+        var roomId = await SeedRoomAsync(owner.PlayerId, accessibility: 0, scenes: new[] { "Home", "Back" });
+        await using (var scope = _factory.Services.CreateAsyncScope())
+        {
+            var db = scope.ServiceProvider.GetRequiredService<DorkNetDbContext>();
+            await db.RoomScenes.Where(s => s.RoomId == roomId)
+                .ExecuteUpdateAsync(s => s.SetProperty(x => x.DataBlobName, "blob-old"));
+            db.RoomDataBlobs.Add(new RoomDataBlobEntity { RoomId = roomId, BlobName = "blob-new", UploadedByPlayerId = owner.PlayerId });
+            await db.SaveChangesAsync();
+        }
+
+        using var api = Client("api", owner);
+        using var response = await api.PostAsync("/api/rooms/v1/restore", new FormUrlEncodedContent(new Dictionary<string, string>
+        {
+            ["roomId"] = roomId.ToString(), ["blobName"] = "blob-new",
+        }));
+        Assert.True(response.IsSuccessStatusCode, await response.Content.ReadAsStringAsync());
+
+        await using var check = _factory.Services.CreateAsyncScope();
+        var checkDb = check.ServiceProvider.GetRequiredService<DorkNetDbContext>();
+        var blobs = await checkDb.RoomScenes.AsNoTracking().Where(s => s.RoomId == roomId)
+            .OrderBy(s => s.OrderIndex).Select(s => s.DataBlobName).ToListAsync();
+        // The entry sub-room follows the restore; other sub-rooms keep theirs.
+        Assert.Equal(new[] { "blob-new", "blob-old" }, blobs);
+    }
+
     [Fact]
     public async Task Startup_repair_restores_a_missing_entry_sub_room_next_to_others()
     {