test(render): Phase A8.F — RetailChaseCamera test hygiene (try/finally reset; fade-on-pull-in)

Code-review follow-ups for Task 3: wrap the flag-off test's CollideCamera reset
in try/finally so an assert failure can't poison downstream tests; add
Update_ProbePullsEyeInClose_FullyFadesPlayer covering retail stage-3 (collided
eye 0.1 m from pivot → PlayerTranslucency 1); tighten probe.Calls assertion to ==1.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tests/AcDream.App.Tests/Rendering/RetailChaseCameraTests.cs

@@ -472,7 +472,7 @@ public class RetailChaseCameraTests
             isOnGround: true, contactPlaneNormal: Vector3.UnitZ, dt: 1f / 60f,
             cellId: 0x100, selfEntityId: 0x5);
 
-        Assert.True(probe.Calls >= 1);
+        Assert.Equal(1, probe.Calls);
         Assert.Equal(collided, cam.Position);
     }
 
@@ -480,18 +480,23 @@ public class RetailChaseCameraTests
     public void Update_FlagOff_DoesNotConsultProbe()
     {
         CameraDiagnostics.CollideCamera = false;
-        var probe = new FakeProbe { ReturnEye = new Vector3(99f, 99f, 99f) };
-        var cam = new RetailChaseCamera { CollisionProbe = probe };
+        try
+        {
+            var probe = new FakeProbe { ReturnEye = new Vector3(99f, 99f, 99f) };
+            var cam = new RetailChaseCamera { CollisionProbe = probe };
 
-        cam.Update(
-            playerPosition: Vector3.Zero, playerYaw: 0f, playerVelocity: Vector3.Zero,
-            isOnGround: true, contactPlaneNormal: Vector3.UnitZ, dt: 1f / 60f,
-            cellId: 0x100, selfEntityId: 0x5);
+            cam.Update(
+                playerPosition: Vector3.Zero, playerYaw: 0f, playerVelocity: Vector3.Zero,
+                isOnGround: true, contactPlaneNormal: Vector3.UnitZ, dt: 1f / 60f,
+                cellId: 0x100, selfEntityId: 0x5);
 
-        Assert.Equal(0, probe.Calls);
-        Assert.NotEqual(new Vector3(99f, 99f, 99f), cam.Position);
-
-        CameraDiagnostics.CollideCamera = true; // reset
+            Assert.Equal(0, probe.Calls);
+            Assert.NotEqual(new Vector3(99f, 99f, 99f), cam.Position);
+        }
+        finally
+        {
+            CameraDiagnostics.CollideCamera = true; // reset even if an assert throws
+        }
     }
 
     [Fact]
@@ -507,4 +512,23 @@ public class RetailChaseCameraTests
 
         Assert.NotEqual(default, cam.View);
     }
+
+    [Fact]
+    public void Update_ProbePullsEyeInClose_FullyFadesPlayer()
+    {
+        // Spec §9 / retail stage 3: when the collided eye ends up very close to
+        // the head-pivot, the player mesh fades. Pivot = (0,0,1.5); a collided
+        // eye 0.1 m above it (≤ the 0.20 m full-fade threshold) → translucency 1.
+        CameraDiagnostics.CollideCamera = true;
+        var pulledIn = new Vector3(0f, 0f, 1.6f);
+        var cam = new RetailChaseCamera { CollisionProbe = new FakeProbe { ReturnEye = pulledIn } };
+
+        cam.Update(
+            playerPosition: Vector3.Zero, playerYaw: 0f, playerVelocity: Vector3.Zero,
+            isOnGround: true, contactPlaneNormal: Vector3.UnitZ, dt: 1f / 60f,
+            cellId: 0x100, selfEntityId: 0x5);
+
+        Assert.Equal(pulledIn, cam.Position);
+        Assert.Equal(1f, cam.PlayerTranslucency, 3);
+    }
 }