test(diagnostics): restore RenderingDiagnostics state in try/finally

Final code review of Phase 1 flagged that the three flag-mutating
tests leaked static state across test boundaries. Wrap each in
try/finally that snapshots IndoorAll on entry and restores it on
exit, matching the PhysicsDiagnosticsTests pattern at line 30-49.
Tests now safe under parallel test runs + future additions.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/AcDream.Core.Tests/Rendering/RenderingDiagnosticsTests.cs

@@ -5,47 +5,77 @@ namespace AcDream.Core.Tests.Rendering;
 
 public sealed class RenderingDiagnosticsTests
 {
+    // Each flag-mutating test snapshots the IndoorAll state on entry and
+    // restores it via try/finally. RenderingDiagnostics is a process-wide
+    // static (env-var-initialized); without restoration a mutated state
+    // leaks into other tests + into parallel test runs. Mirrors the
+    // PhysicsDiagnosticsTests pattern at line 30-49.
+
     [Fact]
     public void IndoorAll_True_TurnsAllFlagsOn()
     {
-        // Reset all flags off first to make the test deterministic
+        bool initial = RenderingDiagnostics.IndoorAll;
-        // regardless of env-var state on the test runner.
+        try
-        RenderingDiagnostics.ProbeIndoorWalkEnabled   = false;
+        {
-        RenderingDiagnostics.ProbeIndoorLookupEnabled = false;
+            // Reset all flags off first to make the test deterministic
-        RenderingDiagnostics.ProbeIndoorUploadEnabled = false;
+            // regardless of env-var state on the test runner.
-        RenderingDiagnostics.ProbeIndoorXformEnabled  = false;
+            RenderingDiagnostics.ProbeIndoorWalkEnabled   = false;
-        RenderingDiagnostics.ProbeIndoorCullEnabled   = false;
+            RenderingDiagnostics.ProbeIndoorLookupEnabled = false;
+            RenderingDiagnostics.ProbeIndoorUploadEnabled = false;
+            RenderingDiagnostics.ProbeIndoorXformEnabled  = false;
+            RenderingDiagnostics.ProbeIndoorCullEnabled   = false;
 
-        RenderingDiagnostics.IndoorAll = true;
+            RenderingDiagnostics.IndoorAll = true;
 
-        Assert.True(RenderingDiagnostics.ProbeIndoorWalkEnabled);
+            Assert.True(RenderingDiagnostics.ProbeIndoorWalkEnabled);
-        Assert.True(RenderingDiagnostics.ProbeIndoorLookupEnabled);
+            Assert.True(RenderingDiagnostics.ProbeIndoorLookupEnabled);
-        Assert.True(RenderingDiagnostics.ProbeIndoorUploadEnabled);
+            Assert.True(RenderingDiagnostics.ProbeIndoorUploadEnabled);
-        Assert.True(RenderingDiagnostics.ProbeIndoorXformEnabled);
+            Assert.True(RenderingDiagnostics.ProbeIndoorXformEnabled);
-        Assert.True(RenderingDiagnostics.ProbeIndoorCullEnabled);
+            Assert.True(RenderingDiagnostics.ProbeIndoorCullEnabled);
-        Assert.True(RenderingDiagnostics.IndoorAll);
+            Assert.True(RenderingDiagnostics.IndoorAll);
+        }
+        finally
+        {
+            RenderingDiagnostics.IndoorAll = initial;
+        }
     }
 
     [Fact]
     public void IndoorAll_False_TurnsAllFlagsOff()
     {
-        RenderingDiagnostics.IndoorAll = true;  // start from all-on
+        bool initial = RenderingDiagnostics.IndoorAll;
-        RenderingDiagnostics.IndoorAll = false;
+        try
+        {
+            RenderingDiagnostics.IndoorAll = true;  // start from all-on
+            RenderingDiagnostics.IndoorAll = false;
 
-        Assert.False(RenderingDiagnostics.ProbeIndoorWalkEnabled);
+            Assert.False(RenderingDiagnostics.ProbeIndoorWalkEnabled);
-        Assert.False(RenderingDiagnostics.ProbeIndoorLookupEnabled);
+            Assert.False(RenderingDiagnostics.ProbeIndoorLookupEnabled);
-        Assert.False(RenderingDiagnostics.ProbeIndoorUploadEnabled);
+            Assert.False(RenderingDiagnostics.ProbeIndoorUploadEnabled);
-        Assert.False(RenderingDiagnostics.ProbeIndoorXformEnabled);
+            Assert.False(RenderingDiagnostics.ProbeIndoorXformEnabled);
-        Assert.False(RenderingDiagnostics.ProbeIndoorCullEnabled);
+            Assert.False(RenderingDiagnostics.ProbeIndoorCullEnabled);
-        Assert.False(RenderingDiagnostics.IndoorAll);
+            Assert.False(RenderingDiagnostics.IndoorAll);
+        }
+        finally
+        {
+            RenderingDiagnostics.IndoorAll = initial;
+        }
     }
 
     [Fact]
     public void IndoorAll_OneOff_ReadsAsFalse()
     {
-        RenderingDiagnostics.IndoorAll = true;
+        bool initial = RenderingDiagnostics.IndoorAll;
-        RenderingDiagnostics.ProbeIndoorCullEnabled = false;  // flip one off
+        try
-        Assert.False(RenderingDiagnostics.IndoorAll);
+        {
+            RenderingDiagnostics.IndoorAll = true;
+            RenderingDiagnostics.ProbeIndoorCullEnabled = false;  // flip one off
+            Assert.False(RenderingDiagnostics.IndoorAll);
+        }
+        finally
+        {
+            RenderingDiagnostics.IndoorAll = initial;
+        }
     }
 
     [Theory]