feat(rendering): port retail one-pass detail material

Replace the building and EnvCell detail replay with retail's exact single-pass stage result, including authored surface opacity, squared detail alpha, final-alpha clipping, and the original subset pipeline/order. Arm the ordered walk command in place to close #471, delete the replay pipelines/shaders, and advance prepared content to recipe 9.

Mutation witnesses (each restored before commit):
- X=a*qA: RetailDetailTextureContractTests.BothShaderFamiliesUseTheSharedOnePassSourceAndDebugPrecedesDetailSample line 174, missing materialAlpha * detail.a * detail.a.
- X*=base alpha: same test line 175, forbidden baseTexel.a found.
- CLIP against base alpha: EnvCellAlphaDrawSourceTests.ClipShaders_UseGreaterEqualForThePerRangeReference line 260, final-X conditional missing.
- second detail draw: EnvCellAlphaDrawSourceTests.DetailOn_EveryEnvCellFamilyDrawsOnceInPlaceWithAuthoredOpacity line 105, Assert.Single saw 2 MDI calls.
- straight-alpha substitution: WalkStaticStreamPopulatorTests.ImmediateBuildingDetail_RetainsOriginalFramebufferFamily line 1244, Additive first failed (only wb-mesh-alpha-1x recorded; InvAlpha also failed).
- omit ordered arm: OrderPreservingSubmitterTests.PrepareThenDraw_OrdinaryBuildingClipBuildingOrdinary_ArmsOnePassInPlace line 305, expected (77,3.5), got (0,0).
- omit atmospheric combine: RetailDetailTextureContractTests.BothShaderFamiliesUseTheSharedOnePassSourceAndDebugPrecedesDetailSample line 173, atmospheric shared include missing.
- drop serialized opacity: ObjectMeshDataSerializerTests.SurfaceOpacity_RoundTripsBitExactlyAndDeterministically line 288, first reported 0.5 bits 1056964608 vs 1065353216.
- stale detail arm: ordered adjacency test line 307, expected following ordinary (0,0), got (77,3.5).
- per-frame surface map: EnvCellAlphaDrawSourceTests.ProductionWholeLeaf_WarmedScanSubmitRhiAndFilteredReplayDoNotAllocate line 178, expected 0 B, got 147456 B.

Verification before commit: shader compiler 23/23; focused App 213/213; Content 75/75; Core Wb 10/10; launcher migration 6/6; Release solution build 0 warnings / 0 errors; git diff --check clean.

tests/AcDream.Launcher.Core.Tests/Installation/ContentMigrationCatalogTests.cs

@@ -53,4 +53,28 @@ public sealed class ContentMigrationCatalogTests
         Assert.Contains("DrawingBSP", plan.Reason, StringComparison.OrdinalIgnoreCase);
         Assert.Contains("CellStruct", plan.Reason, StringComparison.OrdinalIgnoreCase);
     }
+
+    [Fact]
+    public void RecipeEightToNineRequiresOneExplicitFullRebuild()
+    {
+        ContentMigrationPlan plan = ContentMigrationCatalog.Resolve(8, 9);
+
+        Assert.Equal(ContentWorkKind.FullRebuild, plan.Kind);
+        Assert.Equal(8u, plan.FromRecipeVersion);
+        Assert.Equal(9u, plan.TargetRecipeVersion);
+        Assert.Contains("surface opacity", plan.Reason, StringComparison.OrdinalIgnoreCase);
+        Assert.Empty(plan.EffectiveDatIds);
+        Assert.Empty(plan.EffectiveLandblocks);
+    }
+
+    [Fact]
+    public void AnyOlderRecipeToNineCollapsesToOneFullRebuild()
+    {
+        ContentMigrationPlan plan = ContentMigrationCatalog.Resolve(1, 9);
+
+        Assert.Equal(ContentWorkKind.FullRebuild, plan.Kind);
+        Assert.Equal(9u, plan.TargetRecipeVersion);
+        Assert.Contains("CellStruct", plan.Reason, StringComparison.OrdinalIgnoreCase);
+        Assert.Contains("surface opacity", plan.Reason, StringComparison.OrdinalIgnoreCase);
+    }
 }