fix(template-engine): trigger-expression syntax check reports ALL violations/compile errors, not just the first (plan R2-05 T1)

src/ZB.MOM.WW.ScadaBridge.TemplateEngine/Validation/ValidationService.cs

@@ -530,15 +530,17 @@ public class ValidationService
     /// <returns>A human-readable error message if the expression is invalid; <c>null</c> if well-formed.</returns>
     internal static string? CheckExpressionSyntax(string expression)
     {
-        // Authoritative forbidden-API verdict first.
+        // Authoritative forbidden-API verdict first. Report ALL violations, not just
+        // the first, so an operator fixing one forbidden API isn't surprised by a
+        // second on the next deploy attempt (mirrors ScriptCompiler.TryCompile).
         var violations = ScriptTrustValidator.FindViolations(expression);
         if (violations.Count > 0)
-            return $"uses forbidden API: {violations[0]}";
+            return $"uses forbidden API: {string.Join("; ", violations)}";
 
         // Real compile of the bare boolean expression against the trigger globals.
         var errors = RoslynScriptCompiler.Compile(expression, typeof(TriggerCompileSurface));
         if (errors.Count > 0)
-            return $"is not a valid expression: {errors[0]}";
+            return $"is not a valid expression: {string.Join("; ", errors)}";
 
         return null;
     }