revert(render): FW4 slices 4+5 - unanimous tri-review verdict

Reverts 0d6cd5c0 (slice 5) and f3a03efc (slice 4). All three
independent cathedral reviews (fable, opus, external) plus the DAT
geometry ground truth condemned both:

- Slice 5 misidentified its targets: owners 0x4F418012-15 are cell
  0xF4180106''s TORCHES + a prop + a plant (InteriorEntityIdAllocator
  namespace), not the falls - the real waterfall emitters are outdoor
  landblock objects in the 0xC namespace (0xCF418000-13). Moving torch
  flames pre-clear is the owner-reported in-cathedral particle
  regression.
- Slice 4''s straddle rule is invented (retail stages by actual
  shadow-cell membership), and its "emit once" contradicts retail''s
  deliberate mid-frame m_nFrameStamp re-arm @0x005a4886 (a part
  overlapping both scopes legitimately draws twice).

The synthesis of all seven review reports and the adjudicated fix plan
live in docs/research/2026-08-30-cathedral-synthesis.md (next commit).

Hermetic 6,762/0.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/AcDream.App/Rendering/ParticleRenderer.cs

@@ -161,10 +161,6 @@ public sealed unsafe partial class ParticleRenderer : IDisposable
     private readonly List<MeshParticleInstance> _meshRunScratch = new(64);
     private readonly List<ParticleSubmission> _submissionScratch = new(128);
     private readonly List<RuntimeParticleEmitter> _scopedEmitterScratch = new(64);
-
-    // ACDREAM_PROBE_WALK_ROOT companion (throwaway): rate limiter for the
-    // [walk-emit] interior-unattached emitter dump.
-    private uint _probeEmitterDumpCounter;
     private readonly List<DeferredParticleDraw> _deferredAlpha = new(128);
     private DeferredParticleDraw[] _preparedAlpha = new DeferredParticleDraw[256];
     private uint[] _preparedInstanceOffsets = new uint[256];
@@ -251,22 +247,6 @@ public sealed unsafe partial class ParticleRenderer : IDisposable
             _scopedEmitterScratch,
             excludedAttachedOwnerIds,
             unattachedCellScope);
-        // ACDREAM_PROBE_WALK_ROOT companion (throwaway): identify WHICH
-        // emitters ride the interior-unattached route (the falls hunt) —
-        // owner cell, anchor position, attachment.
-        if (AcDream.Core.Rendering.RenderingDiagnostics.ProbeWalkRootEnabled
-            && unattachedCellScope == UnattachedEmitterCellScope.InteriorCells
-            && ++_probeEmitterDumpCounter % 120 == 0)
-        {
-            foreach (var em in _scopedEmitterScratch)
-            {
-                Console.WriteLine(
-                    $"[walk-emit] cell={em.OwnerCellId:x8} attached={em.AttachedObjectId:x} "
-                    + $"anchor=({em.AnchorPos.X:F1},{em.AnchorPos.Y:F1},{em.AnchorPos.Z:F1}) "
-                    + $"active={em.ActiveCount} "
-                    + $"phase={AcDream.Core.Rendering.RenderingDiagnostics.WalkRootPhase}");
-            }
-        }
         Matrix4x4.Invert(camera.View, out Matrix4x4 invView);
         Vector3 cameraRight = Vector3.Normalize(new Vector3(invView.M11, invView.M12, invView.M13));
         Vector3 cameraUp = Vector3.Normalize(new Vector3(invView.M21, invView.M22, invView.M23));

src/AcDream.App/Rendering/RetailPViewRenderer.cs

@@ -71,28 +71,6 @@ public sealed class RetailPViewRenderer
     private readonly HashSet<uint> _cellParticleOwnerScratch = new();
     private readonly HashSet<uint> _dynamicParticleOwnerScratch = new();
 
-    // FW4 slice 4: owners whose particles ALREADY submitted in the
-    // pre-clear outside stage this frame (interior roots only). The last
-    // pass subtracts them — retail submits an emitter's polys at its
-    // object's FIRST draw (the landscape stage for anything overlapping
-    // outdoor shadow cells) and drains them at the pre-clear boundary
-    // flush over true landscape depth; a straddler re-emitted post-clear
-    // has no outdoor depth left to occlude it (the cathedral falls
-    // shine-through, fourth surface).
-    private readonly HashSet<uint> _preClearParticleOwnerScratch = new();
-
-    // FW4 slice 5: interior flood-cell STATICS whose bounds straddle their
-    // cell's exit-portal plane (the cathedral falls — EnvCell stab-list
-    // objects hanging out over the lake). Retail draws such an object
-    // during LScape::draw via the outdoor shadow-cell lists (DrawBlock
-    // pc:430056-430064, once per overlapped shadow cell), so its particles
-    // submit in the landscape scope and drain at the pre-clear boundary
-    // flush over true terrain depth; the cell's own post-clear turn skips
-    // them (drawn-once). Computed after Collect from the walk's flood;
-    // submitted by the pre-clear closure; subtracted from the post-replay
-    // cell-owners union.
-    private readonly HashSet<uint> _preClearCellStaticOwnerScratch = new();
-
     // MP-Alloc (2026-07-05): the frame's entity partition (ByCell/OutdoorStatic/
     // Dynamics), reused across frames instead of `new`ing a Result (a Dictionary
     // + 2 Lists, plus one List<WorldEntity> per visible cell) every DrawInside
@@ -177,7 +155,6 @@ public sealed class RetailPViewRenderer
         passes.BeginFrame();
         RecycleLookInFrames();
         ResetBuildingGroups();
-        _preClearParticleOwnerScratch.Clear();
 
         var pvFrame = PortalVisibilityBuilder.Build(
             ctx.RootCell,
@@ -366,15 +343,9 @@ public sealed class RetailPViewRenderer
                 walkExecutor!, ctx, clipAssembly, clearInteriorDepth, drawExitSeals);
             walkDriver = new Walk.WalkFrameDriver(walkExecutor!.Dispatcher, leafRenderer, _walkWorldData);
 
-            if (AcDream.Core.Rendering.RenderingDiagnostics.ProbeWalkRootEnabled)
-            {
-                AcDream.Core.Rendering.RenderingDiagnostics.WalkPortalProbeThisFrame =
-                    _probeWalkRootFrame % 90 == 0;
-            }
             walkDriver.Collect(
                 _frameWalk, ctx.ViewerCellId, walkCameraCell, walkLandscape, walkContext,
                 ctx.ViewProjection, ctx.CameraWorldPosition);
-            AcDream.Core.Rendering.RenderingDiagnostics.WalkPortalProbeThisFrame = false;
 
             // FW4 slice 1: an interior root's terrain/sky/punch clip slices
             // come from THE WALK'S OWN outside_view — retail's one
@@ -594,37 +565,6 @@ public sealed class RetailPViewRenderer
                 }
             }
 
-            // FW4 slice 5: classify the interior flood cells' STATICS by the
-            // exit-plane straddle test — a straddler's particles (the
-            // cathedral falls: EnvCell stab objects hanging over the lake)
-            // submit pre-clear like retail's outdoor shadow-cell draw; see
-            // _preClearCellStaticOwnerScratch's field comment. GetCellStatics
-            // is per-frame cached, so this also pre-warms the post-replay
-            // cell-owners pass.
-            _preClearCellStaticOwnerScratch.Clear();
-            if (walkActive && !ctx.RootCell.IsOutdoorNode)
-            {
-                foreach (uint cellId in walkDriver!.VisitedCells)
-                {
-                    if ((cellId & 0xFFFFu) < 0x100u || _lookInCellIds.Contains(cellId))
-                        continue;
-                    LoadedCell? staticCell = ctx.Cells.Find(cellId);
-                    if (staticCell is null)
-                        continue;
-                    Walk.WalkFrameStaticRecords cellRecords =
-                        _walkWorldData!.GetCellStatics(cellId);
-                    foreach (RenderProjectionRecord record in cellRecords.Records)
-                    {
-                        if (record.Source.LocalEntityId == 0)
-                            continue;
-                        Vector3 c = (record.Bounds.Minimum + record.Bounds.Maximum) * 0.5f;
-                        float r = (record.Bounds.Maximum - record.Bounds.Minimum).Length() * 0.5f;
-                        if (SphereStraddlesExitPlane(staticCell, c, r))
-                            _preClearCellStaticOwnerScratch.Add(record.Source.LocalEntityId);
-                    }
-                }
-            }
-
             if (walkActive)
             {
                 // Campaign FW3.2b-2: the walk owns every static draw —
@@ -657,17 +597,6 @@ public sealed class RetailPViewRenderer
                     // BEFORE the pre-clear drain so they composite against
                     // still-true landscape depth, never the seals.
                     SubmitWalkLandscapeStaticParticles(ctx, walkExecutor!, capturedDriver);
-                    // FW4 slice 5: straddling flood-cell statics' emitters
-                    // (the falls) — retail's shadow-cell landscape draw.
-                    if (_preClearCellStaticOwnerScratch.Count > 0)
-                    {
-                        _preClearParticleOwnerScratch.UnionWith(
-                            _preClearCellStaticOwnerScratch);
-                        passes.DrawLandscapeStaticParticles(
-                            ctx,
-                            new RetailPViewLandscapeStaticParticleContext(
-                                _preClearCellStaticOwnerScratch));
-                    }
                     passes.UseIndoorMembershipOnlyRouting();
                     DrawLandscapeDynamicsPhase(
                         ctx,
@@ -1463,10 +1392,6 @@ public sealed class RetailPViewRenderer
                 continue;
             UnionRecordOwners(_walkWorldData!.GetCellStatics(cellId), _cellParticleOwnerScratch);
         }
-        // FW4 slice 5: exit-plane straddlers (the falls) already emitted at
-        // the pre-clear boundary — retail's shadow-cell landscape draw;
-        // every owner emits exactly once.
-        _cellParticleOwnerScratch.ExceptWith(_preClearCellStaticOwnerScratch);
         if (_cellParticleOwnerScratch.Count > 0)
         {
             passes.DrawCellParticles(
@@ -1568,26 +1493,13 @@ public sealed class RetailPViewRenderer
                 });
         }
 
-        // Late-particle union submission. OUTDOOR root: DynamicLast owners
+        // Late-particle union submission — DynamicLast owners excluded, same
-        // excluded (both stages drain at the same final flush there — a
+        // as DrawLandscapeThroughOutsideView's own final submission.
-        // duplicate submission would double-composite), matching
+        if (frameEntityPasses is not null)
-        // DrawLandscapeThroughOutsideView's own final submission. INTERIOR
-        // root (FW4 slice 4): the outside-stage owners — exit-plane
-        // STRADDLERS included — submit HERE, pre-clear, and the last pass
-        // subtracts them instead: retail submits an emitter's polys at its
-        // object's FIRST draw (the landscape stage) and drains them at the
-        // pre-clear boundary flush over true landscape depth; the former
-        // except-here/emit-last placement left a straddler's outside half
-        // with no depth to occlude it after the clear (the cathedral falls
-        // bleeding through terrain and water, probe-pinned:
-        // outside=1 cone=1 yet phase=post).
-        if (frameEntityPasses is not null && ctx.RootCell.IsOutdoorNode)
         {
             RenderFrameRouteOwnerSelector.ExceptRoute(
                 _staticParticleUnionScratch, in frameView, RenderFrameCandidateRoute.DynamicLast);
         }
-        if (!ctx.RootCell.IsOutdoorNode)
-            _preClearParticleOwnerScratch.UnionWith(_staticParticleUnionScratch);
         if (_staticParticleUnionScratch.Count > 0)
         {
             passes.DrawLandscapeStaticParticles(
@@ -2245,10 +2157,6 @@ public sealed class RetailPViewRenderer
                 RenderFrameCandidateRoute.DynamicLast,
                 0,
                 0);
-            // FW4 slice 4: owners already emitted pre-clear (the outside
-            // stage's late union — straddlers included) emit ONCE; see
-            // _preClearParticleOwnerScratch's field comment.
-            _dynamicParticleOwnerScratch.ExceptWith(_preClearParticleOwnerScratch);
 
             passes.UseIndoorMembershipOnlyRouting();
             DrawEntityRouteOrLegacy(
@@ -2383,9 +2291,6 @@ public sealed class RetailPViewRenderer
                 if (InteriorEntityPartition.IsIndoorCellId(e.ParentCellId))
                     _dynamicParticleOwnerScratch.Add(e.Id);
         }
-        // FW4 slice 4: pre-clear-emitted owners (straddlers) emit once —
-        // see _preClearParticleOwnerScratch's field comment.
-        _dynamicParticleOwnerScratch.ExceptWith(_preClearParticleOwnerScratch);
         if (_dynamicParticleOwnerScratch.Count > 0)
             passes.DrawDynamicsParticles(ctx, _dynamicParticleOwnerScratch);
     }
@@ -2681,16 +2586,6 @@ public sealed class RetailPViewRenderer
         if (cell is null)
             return false;
 
-        return SphereStraddlesExitPlane(cell, sphereCenter, sphereRadius);
-    }
-
-    /// <summary>The exit-plane straddle test shared by the #118 dynamic
-    /// stage split and the FW4 slice-5 cell-static particle split — retail
-    /// draws a straddling object once per overlapped outdoor shadow cell
-    /// inside LScape::draw (DrawBlock pc:430056-430064).</summary>
-    internal static bool SphereStraddlesExitPlane(
-        LoadedCell cell, Vector3 sphereCenter, float sphereRadius)
-    {
         var localC = Vector3.Transform(sphereCenter, cell.InverseWorldTransform);
         int n = Math.Min(cell.Portals.Count, cell.ClipPlanes.Count);
         for (int i = 0; i < n; i++)

src/AcDream.App/Rendering/Walk/WalkPView.cs

@@ -119,14 +119,6 @@ public sealed class WalkPView
                         flags.InView = true;   // portal polygon faces the viewer
                     }
                 }
-                if (AcDream.Core.Rendering.RenderingDiagnostics.WalkPortalProbeThisFrame)
-                {
-                    Console.WriteLine(
-                        $"[walk-portal] init cell={cell.CellId:x8} i={i} "
-                        + $"dest={cell.Portals[i].OtherCellId:x8} d={d:F3} "
-                        + $"pside={cell.Portals[i].PortalSide} "
-                        + $"inview={(flags.InView ? 1 : 0)}");
-                }
             }
 
             if (flags.InView)
@@ -209,12 +201,6 @@ public sealed class WalkPView
                     cell, portal.PortalSide,
                     cell.PortalPolygons[portal.PolygonIndex],
                     doClip: true, ctx, _clipScratch);
-                if (AcDream.Core.Rendering.RenderingDiagnostics.WalkPortalProbeThisFrame)
-                {
-                    Console.WriteLine(
-                        $"[walk-portal] clip cell={cell.CellId:x8} view={i} j={j} "
-                        + $"dest={portal.OtherCellId:x8} n={n}");
-                }
                 if (n == 0) continue;
 
                 if (portal.OtherCellId == 0xFFFFFFFFu)