feat(render): Phase A8 — indoor visibility + streaming fixes batch

Lands the working A8 indoor-rendering and streaming fixes accumulated this
session. User has verified these visually to some degree (e.g. lifestone /
translucent meshes confirmed fine under the FrontFace flip; bridge / wall /
collision regressions confirmed fixed after travel); not every path has been
exhaustively gated. The cellar-flap defect remains OPEN and will be solved
the retail-faithful way via a dedicated brainstorm (see handoff docs).

Rendering core (reviewed, high confidence):
- EnvCellRenderer SSBO stride fix: upload packed Matrix4x4[] (64B) instead of
  the 80B CPU InstanceData struct the shader never expected — fixes the
  transform/texture "explosion" for any draw with >1 instance (cells that
  dedupe to a shared cellGeomId). Real root cause.
- WB-style global FrontFace(CW) + per-batch CullMode carried through the MDI
  layout (GroupKey + BuildIndirectArrays + DrawIndirectRange split into
  same-cull runs with absolute uDrawIDOffset per run).
- EntitySet partitioning (IndoorPass / OutdoorScenery / LiveDynamic) +
  WorldEntity.BuildingShellAnchorCellId so building shells scope to their
  dat-derived building cell instead of rendering everywhere.
- RenderOutsideInAcdream (look into buildings from outside) +
  CollectVisiblePortalBuildings frustum cull of portal bounds.
- Sky-when-inside-building + per-cell audit probe + GL-state probe.

Streaming / perf (test-covered; not independently code-reviewed this session):
- Near/far priority queues so near work wins over far; PromoteToNear carries
  full landblock + mesh data; LandblockEntriesWithoutAnimatedIndex avoids
  rebuilding the animated-lookup dict in the hot draw path. Fixes the
  bridge-not-appearing / missing-walls / broken-collision-after-travel
  regressions and improves post-transition FPS.

Tooling + docs:
- tools/A8CellAudit: offline dat cell/portal/building dumper (portals +
  buildings modes) — reproduces the cellar-flap investigation with no launch.
- docs/research cellar-flap root-cause + option-2 handoff (the didInsideStencil
  double-duty finding + the WB-recursive design decision + brainstorm prompt),
  entity-taxonomy, replan, issue-78 visibility investigation.

Diagnostics retained on purpose: ACDREAM_A8_DIAG_* gates, portal_stencil.vert
provisional pos.w clamp, and the probe families are kept (env-var gated, zero
cost when off) because the pending option-2 cellar-flap brainstorm needs them.
Strip in the option-2 ship commit.

Indoor branch stays behind ACDREAM_A8_INDOOR_BRANCH=1 (default off = pre-A8
visual). Build green; App tests + Core (streaming/dispatcher/loader) tests pass.

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

tests/AcDream.Core.Tests/Streaming/StreamingControllerTwoTierTests.cs

@@ -99,16 +99,25 @@ public class StreamingControllerTwoTierTests
         state.AddLandblock(lb);
         Assert.Empty(state.Entities);
 
-        // Streamer pushes a Promoted result carrying the entity layer.
-        var promoted = new LandblockStreamResult.Promoted(
+        // Streamer pushes a Promoted result carrying the full near landblock.
+        var promotedLb = new LoadedLandblock(
             lbId,
-            new[] { new WorldEntity {
+            Heightmap: null!,
+            Entities: new[] { new WorldEntity {
                 Id = 7, SourceGfxObjOrSetupId = 0,
                 Position = System.Numerics.Vector3.Zero,
                 Rotation = System.Numerics.Quaternion.Identity,
                 MeshRefs = System.Array.Empty<MeshRef>() } });
+        var promotedMesh = new LandblockMeshData(
+            System.Array.Empty<TerrainVertex>(),
+            System.Array.Empty<uint>());
+        var promoted = new LandblockStreamResult.Promoted(
+            lbId,
+            promotedLb,
+            promotedMesh);
         var queue = new Queue<LandblockStreamResult>();
         queue.Enqueue(promoted);
+        int applyPromotedCount = 0;
 
         var ctrl = new StreamingController(
             enqueueLoad: (id, kind) => loads.Add((id, kind)),
@@ -119,7 +128,12 @@ public class StreamingControllerTwoTierTests
                 while (batch.Count < max && queue.Count > 0) batch.Add(queue.Dequeue());
                 return batch;
             },
-            applyTerrain: (_, _) => { },
+            applyTerrain: (appliedLb, appliedMesh) =>
+            {
+                applyPromotedCount++;
+                Assert.Same(promotedLb, appliedLb);
+                Assert.Same(promotedMesh, appliedMesh);
+            },
             state: state,
             nearRadius: 2,
             farRadius: 2);
@@ -128,6 +142,7 @@ public class StreamingControllerTwoTierTests
 
         // Promoted routes to AddEntitiesToExistingLandblock — the entity is now
         // merged into the existing LB record.
+        Assert.Equal(1, applyPromotedCount);
         Assert.Equal(1, state.Entities.Count);
         Assert.Equal(7u, state.Entities[0].Id);
     }