feat(render): Phase A8 RR5 — WbDrawDispatcher Draw(cellIds:) overload

Adds a new public overload accepting an explicit IReadOnlyCollection<uint>
cellIds (the camera-buildings' EnvCellIds) instead of a BFS-derived
visibility set. Used by RR7's IndoorPass to scope indoor rendering to the
camera-buildings' cells, not the full portal BFS (which causes Issues A+C).

Pure-data test helper WalkEntitiesForTestByCellIds added alongside the
production overload, mirroring the WalkEntitiesForTest pattern.

The overload internally delegates to the existing visibleCellIds path —
the dispatcher's semantic stays the same; only the caller's intent differs
(explicit cell list vs visibility-derived).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/AcDream.App/Rendering/Wb/WbDrawDispatcher.cs

@@ -1089,6 +1089,41 @@ public sealed unsafe class WbDrawDispatcher : IDisposable
         }
     }
 
+    /// <summary>
+    /// Phase A8 RR5 (2026-05-26): per-building draw overload. Walks only
+    /// entities whose ParentCellId is in <paramref name="cellIds"/>, plus
+    /// outdoor-style entities matching the EntitySet partition. Used by
+    /// the indoor render branch to scope rendering to the camera-buildings'
+    /// cells.
+    ///
+    /// <para>Mirrors the existing visibleCellIds-based Draw but with an
+    /// explicit cell list (not the BFS-derived visibility set). The semantic
+    /// difference is at the caller: cellIds = the camera-buildings' EnvCellIds,
+    /// not the portal BFS result. The dispatcher's internal logic is identical
+    /// — it filters indoor entities by membership in the provided set.</para>
+    /// </summary>
+    public void Draw(
+        ICamera camera,
+        IEnumerable<(uint LandblockId, Vector3 AabbMin, Vector3 AabbMax,
+                     IReadOnlyList<WorldEntity> Entities,
+                     IReadOnlyDictionary<uint, WorldEntity>? AnimatedById)> landblockEntries,
+        IReadOnlyCollection<uint> cellIds,
+        FrustumPlanes? frustum = null,
+        uint? neverCullLandblockId = null,
+        HashSet<uint>? animatedEntityIds = null,
+        EntitySet set = EntitySet.All)
+    {
+        // Adapt IReadOnlyCollection<uint> → HashSet<uint> for the existing path.
+        // If the caller already passed a HashSet, avoid re-wrapping.
+        HashSet<uint> cellIdSet = cellIds is HashSet<uint> hs ? hs : new HashSet<uint>(cellIds);
+        Draw(camera, landblockEntries,
+             frustum: frustum,
+             neverCullLandblockId: neverCullLandblockId,
+             visibleCellIds: cellIdSet,
+             animatedEntityIds: animatedEntityIds,
+             set: set);
+    }
+
     private static IndirectGroupInput ToInput(InstanceGroup g) => new(
         IndexCount:    g.IndexCount,
         FirstIndex:    g.FirstIndex,
@@ -1400,6 +1435,34 @@ public sealed unsafe class WbDrawDispatcher : IDisposable
         return output;
     }
 
+    /// <summary>
+    /// Phase A8 RR5 (2026-05-26): pure-data walk for the explicit cellIds
+    /// overload. Used by RR7's IndoorPass to render only the camera-buildings'
+    /// cells (instead of the visibility-derived set).
+    ///
+    /// <para>Indoor entities (ParentCellId set) gated by membership in
+    /// <paramref name="cellIds"/>. Building shells (IsBuildingShell) pass
+    /// unconditionally when <paramref name="set"/> == IndoorPass. Outdoor
+    /// scenery is excluded by the EntitySet partition (no cell-list gate
+    /// needed — EntityMatchesSet handles it).</para>
+    /// </summary>
+    public static List<uint> WalkEntitiesForTestByCellIds(
+        IEnumerable<AcDream.Core.World.WorldEntity> entities,
+        IReadOnlyCollection<uint> cellIds,
+        EntitySet set)
+    {
+        var result = new List<uint>();
+        foreach (var entity in entities)
+        {
+            if (!EntityMatchesSet(entity, set)) continue;
+            if (entity.MeshRefs.Count == 0) continue;
+            if (entity.ParentCellId.HasValue && !cellIds.Contains(entity.ParentCellId.Value))
+                continue;
+            result.Add(entity.Id);
+        }
+        return result;
+    }
+
     public void Dispose()
     {
         if (_disposed) return;