fix(camera): port retail offset adjustment laws

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

@@ -537,14 +537,50 @@ public class RetailChaseCameraTests
     }
 
     [Fact]
-    public void AdjustDistance_ClampsToRange()
+    public void AdjustDistance_UsesRetailMultiplicativeScale()
     {
         var cam = new RetailChaseCamera { Distance = 5f };
-        cam.AdjustDistance(-100f);
-        Assert.Equal(RetailChaseCamera.DistanceMin, cam.Distance);
+        cam.AdjustDistance(+1f);
+        Assert.Equal(6f, cam.Distance, 5);
 
-        cam.AdjustDistance(+200f);
-        Assert.Equal(RetailChaseCamera.DistanceMax, cam.Distance);
+        cam.AdjustDistance(-1f);
+        Assert.Equal(4.8f, cam.Distance, 5);
+    }
+
+    [Fact]
+    public void AdjustDistance_RefusesWholeWriteAtRetailComponentAndNearLimits()
+    {
+        var far = new RetailChaseCamera
+        {
+            Distance = 9.9f,
+            Pitch = 0f,
+            YawOffset = 0f,
+        };
+        far.AdjustDistance(+1f);
+        Assert.Equal(9.9f, far.Distance, 5);
+
+        var near = new RetailChaseCamera
+        {
+            Distance = 0.55f,
+            Pitch = 0f,
+        };
+        near.AdjustDistance(-1f);
+        Assert.Equal(0.55f, near.Distance, 5);
+    }
+
+    [Fact]
+    public void AdjustDistance_DiagonalOrbitUsesIndependentRetailXAndYLimits()
+    {
+        var cam = new RetailChaseCamera
+        {
+            Distance = 12f,
+            Pitch = 0f,
+            YawOffset = MathF.PI / 4f,
+        };
+
+        cam.AdjustDistance(+0.5f);
+
+        Assert.Equal(13.2f, cam.Distance, 5);
     }
 
     [Fact]
@@ -579,18 +615,37 @@ public class RetailChaseCameraTests
         cam.AdjustDistance(1f);
 
         Assert.False(cam.IsInHead);
-        Assert.Equal(RetailChaseCamera.DistanceMin + 1f, cam.Distance);
+        Assert.Equal(MathF.Sqrt(0.6f * 0.6f + 0.5f * 0.5f), cam.Distance, 5);
     }
 
     [Fact]
-    public void AdjustPitch_ClampsToRange()
+    public void AdjustPitch_UsesRetailEightDegreeRotationAndPreservesLength()
     {
-        var cam = new RetailChaseCamera { Pitch = 0f };
-        cam.AdjustPitch(-10f);
-        Assert.Equal(RetailChaseCamera.PitchMin, cam.Pitch);
+        var cam = new RetailChaseCamera { Distance = 5f, Pitch = 0f };
+        cam.AdjustPitch(+1f);
 
-        cam.AdjustPitch(+10f);
-        Assert.Equal(RetailChaseCamera.PitchMax, cam.Pitch);
+        Assert.Equal(RetailChaseCamera.OffsetAngleRadians, cam.Pitch, 6);
+        Assert.Equal(5f, cam.Distance, 6);
+    }
+
+    [Fact]
+    public void AdjustPitch_RefusesWholeWriteBelowRetailVerticalLimit()
+    {
+        var cam = new RetailChaseCamera { Distance = 3f, Pitch = -0.55f };
+        float before = cam.Pitch;
+
+        cam.AdjustPitch(-1f);
+
+        Assert.Equal(before, cam.Pitch);
+        Assert.Equal(3f, cam.Distance);
+    }
+
+    [Fact]
+    public void AdjustYaw_UsesRetailEightDegreeRotationUnit()
+    {
+        var cam = new RetailChaseCamera();
+        cam.AdjustYaw(+1f);
+        Assert.Equal(RetailChaseCamera.OffsetAngleRadians, cam.YawOffset, 6);
     }
 
     // ── Camera collision (A8.F) ───────────────────────────────────────