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>

src/AcDream.App/Streaming/LandblockStreamer.cs

@@ -159,6 +159,9 @@ public sealed class LandblockStreamer : IDisposable
 
     private void WorkerLoop()
     {
+        var highPriority = new Queue<LandblockStreamJob>();
+        var lowPriority = new Queue<LandblockStreamJob>();
+
         try
         {
             // Safe to block: this is a dedicated worker thread with no
@@ -169,14 +172,24 @@ public sealed class LandblockStreamer : IDisposable
             // simple thread-start shape.
             while (!_cancel.Token.IsCancellationRequested)
             {
-                if (!_inbox.Reader.WaitToReadAsync(_cancel.Token).AsTask().GetAwaiter().GetResult())
+                if (highPriority.Count == 0 &&
+                    lowPriority.Count == 0 &&
+                    !_inbox.Reader.WaitToReadAsync(_cancel.Token).AsTask().GetAwaiter().GetResult())
+                {
                     break;
+                }
 
                 while (_inbox.Reader.TryRead(out var job))
-                {
-                    if (_cancel.Token.IsCancellationRequested) return;
-                    HandleJob(job);
-                }
+                    EnqueuePrioritized(job, highPriority, lowPriority);
+
+                if (highPriority.Count == 0 && lowPriority.Count == 0)
+                    continue;
+
+                if (_cancel.Token.IsCancellationRequested) return;
+                var next = highPriority.Count > 0
+                    ? highPriority.Dequeue()
+                    : lowPriority.Dequeue();
+                HandleJob(next);
             }
         }
         catch (OperationCanceledException) { /* graceful shutdown */ }
@@ -192,6 +205,55 @@ public sealed class LandblockStreamer : IDisposable
         }
     }
 
+    private static void EnqueuePrioritized(
+        LandblockStreamJob job,
+        Queue<LandblockStreamJob> highPriority,
+        Queue<LandblockStreamJob> lowPriority)
+    {
+        if (job is LandblockStreamJob.Load
+            {
+                Kind: LandblockStreamJobKind.LoadNear or LandblockStreamJobKind.PromoteToNear
+            } high)
+        {
+            // Near-tier jobs are visible-content critical. They supersede an
+            // older queued LoadFar for the same landblock: LoadNear obviously
+            // loads everything, and PromoteToNear now carries mesh data so the
+            // render thread can run the full near-tier apply side effects. If a
+            // LoadFar is already being processed, the single worker naturally
+            // finishes it before the promotion is dequeued.
+            RemoveLowPriorityJobsForLandblock(
+                lowPriority,
+                high.LandblockId,
+                removeLoadFar: true,
+                removeUnload: true);
+            highPriority.Enqueue(job);
+            return;
+        }
+
+        lowPriority.Enqueue(job);
+    }
+
+    private static void RemoveLowPriorityJobsForLandblock(
+        Queue<LandblockStreamJob> queue,
+        uint landblockId,
+        bool removeLoadFar,
+        bool removeUnload)
+    {
+        int count = queue.Count;
+        for (int i = 0; i < count; i++)
+        {
+            var job = queue.Dequeue();
+            bool remove = job.LandblockId == landblockId && job switch
+            {
+                LandblockStreamJob.Load { Kind: LandblockStreamJobKind.LoadFar } => removeLoadFar,
+                LandblockStreamJob.Unload => removeUnload,
+                _ => false
+            };
+            if (!remove)
+                queue.Enqueue(job);
+        }
+    }
+
     private void HandleJob(LandblockStreamJob job)
     {
         switch (job)
@@ -212,6 +274,19 @@ public sealed class LandblockStreamer : IDisposable
                             load.LandblockId, "LandblockLoader.Load returned null"));
                         break;
                     }
+                    if (load.Kind == LandblockStreamJobKind.PromoteToNear)
+                    {
+                        var promotedMesh = _buildMeshOrNull(load.LandblockId, lb);
+                        if (promotedMesh is null)
+                        {
+                            _outbox.Writer.TryWrite(new LandblockStreamResult.Failed(
+                                load.LandblockId, "buildMeshOrNull returned null"));
+                            break;
+                        }
+                        _outbox.Writer.TryWrite(new LandblockStreamResult.Promoted(
+                            load.LandblockId, lb, promotedMesh));
+                        break;
+                    }
                     var mesh = _buildMeshOrNull(load.LandblockId, lb);
                     if (mesh is null)
                     {