revert(render): BR-2 depth discipline - the gate proved #108 is MEMBERSHIP, not depth

Visual gate (2026-06-11) on the seal+punch build, then on the punch-reverted
build, isolated the truth:
- With the punch wired: #108 (cellar grass-sweep) gone BUT the player/NPCs
  go transparent by exactly their overlap with any doorway viewed from
  outside (the far-Z punch erases the depth of dynamic objects standing in
  the aperture, so the interior paints over them).
- With ONLY the punch reverted (seal+full-clear kept): characters render
  correctly AND #108 is BACK.

The punch is wired for OUTDOOR roots + the look-in path ONLY; it never runs
on a clean interior (cellar) frame. For it to have suppressed #108, the
cellar-transition frames must render through the OUTDOOR root -> the player
is being classified OUTDOOR mid-cellar (the known #112/#106 cellar
membership ping-pong). So:
- #108 is a MEMBERSHIP bug (render is downstream of membership); the punch
  was MASKING it, harmfully. Re-attributed to the membership track.
- The interior-root SEAL addresses a case that is NOT #108 (confirmed: #108
  isn't an interior-root frame), so it has no verified visible effect yet.

Per no-workarounds + verify-before-layering: reverted ALL of BR-2's depth
machinery (seal, punch, the per-slice->full-clear swap) to the pre-BR-2
baseline (restored from 6cba950). The phantom-site probe (6cba950) is kept.
PortalDepthMaskRenderer.cs is KEPT as a RESERVED, unwired primitive (it is
verified-correct; the depth discipline will be rebuilt during BR-3 with
dynamics-after-interior ordering, where it can be verified against the
shell-chop deletion).

What survives from this session's execution: BR-1 (already-equivalent,
695eca2) stands. #108 moves to membership. BR-2 to be re-approached under
BR-3 with correct ordering. No net production behavior change vs 6cba950.

Suites: build green, App 226 green.

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

src/AcDream.App/Rendering/RetailPViewRenderer.cs

@@ -231,16 +231,8 @@ public sealed class RetailPViewRenderer
             ctx.DrawLandscapeSlice(new RetailPViewLandscapeSliceContext(slice, partition.Outdoor));
         }
 
-        // BR-2: retail clears the FULL depth buffer ONCE between the outside
-        // stage and the interior stage (PView::DrawCells, Ghidra 0x005a4840 —
-        // Clear gated on portalsDrawnCount; the exact gate semantics is a plan
-        // open question, staged here as "any outside slice drawn"), then
-        // re-stamps every outside-leading portal's TRUE depth (the seals,
-        // DrawExitPortalMasks below). The old per-slice scissored AABB clear
-        // was the wrong shape (AABB ⊇ aperture polygon) and had no seal after
-        // it — the #108 mechanism.
-        if (clipAssembly.OutsideViewSlices.Length > 0)
-            ctx.ClearDepthForInterior?.Invoke();
+        foreach (var slice in clipAssembly.OutsideViewSlices)
+            ctx.ClearDepthSlice?.Invoke(slice);
 
         UseIndoorMembershipOnlyRouting();
     }
@@ -583,12 +575,7 @@ public sealed class RetailPViewDrawContext : IRetailPViewCellDrawContext
         IReadOnlyDictionary<uint, WorldEntity>? AnimatedById)> LandblockEntries { get; init; }
     public required Action<uint> SetTerrainClipUbo { get; init; }
     public required Action<RetailPViewLandscapeSliceContext> DrawLandscapeSlice { get; init; }
-
-    /// <summary>BR-2: one full-buffer depth clear between the outside stage and the
-    /// interior stage (retail PView::DrawCells, Ghidra 0x005a4840). Null for outdoor
-    /// roots — outdoors the interiors must depth-test against terrain + exteriors and
-    /// appear only through real apertures (the BR-2 commit-2 punch).</summary>
-    public Action? ClearDepthForInterior { get; init; }
+    public Action<ClipViewSlice>? ClearDepthSlice { get; init; }
     public Action<RetailPViewCellSliceContext>? DrawExitPortalMasks { get; init; }
     public Action<RetailPViewCellSliceContext>? DrawCellParticles { get; init; }
     public Action<RetailPViewFrameResult>? EmitDiagnostics { get; init; }