perf(runtime): O(1) attribute resolution, precomputed types, coalesced static writes, shared JSON options

src/ZB.MOM.WW.ScadaBridge.CentralUI/ScriptAnalysis/ScriptAnalysisService.cs

@@ -177,6 +177,15 @@ public class ScriptAnalysisService
     private const int SandboxMaxConsoleChars = 32_000;
     private const int SandboxMaxReturnJsonChars = 32_000;
 
+    /// <summary>
+    /// Shared options for the per-Test-Run return-value JSON serialize in
+    /// <see cref="SerializeReturn"/> (perf remediation, arch-review WP1.5) — avoids
+    /// allocating a new <see cref="JsonSerializerOptions"/> per run. Settings preserved
+    /// exactly.
+    /// </summary>
+    private static readonly JsonSerializerOptions SandboxReturnJsonOptions =
+        new() { WriteIndented = true };
+
     private const int SandboxMaxCallSharedDepth = 16;
 
     /// <summary>
@@ -520,7 +529,7 @@ public class ScriptAnalysisService
         var typeName = value.GetType().Name;
         try
         {
-            var json = JsonSerializer.Serialize(value, new JsonSerializerOptions { WriteIndented = true });
+            var json = JsonSerializer.Serialize(value, SandboxReturnJsonOptions);
             if (json.Length > SandboxMaxReturnJsonChars)
                 json = json[..SandboxMaxReturnJsonChars] + "\n… (truncated)";
             return (json, typeName);