feat(typescript): add sortModelPropertiesByName helper method

Add a protected helper method to sort model properties alphabetically,
ensuring deterministic code generation across all TypeScript generators.

The method sorts vars, allVars, requiredVars, optionalVars, readOnlyVars,
readWriteVars, and parentVars by property name.

Author: scarf005

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractTypeScriptClientCodegen.java

@@ -1023,6 +1023,21 @@ protected void addImport(CodegenModel m, String type) {
         }
     }
 
+    /**
+     * Sort model properties alphabetically to ensure deterministic code generation.
+     * Subclasses that override postProcessModels should call this method for each CodegenModel.
+     */
+    protected void sortModelPropertiesByName(CodegenModel cm) {
+        Comparator<CodegenProperty> comparator = Comparator.comparing(p -> p.name);
+        Collections.sort(cm.vars, comparator);
+        Collections.sort(cm.allVars, comparator);
+        Collections.sort(cm.requiredVars, comparator);
+        Collections.sort(cm.optionalVars, comparator);
+        Collections.sort(cm.readOnlyVars, comparator);
+        Collections.sort(cm.readWriteVars, comparator);
+        Collections.sort(cm.parentVars, comparator);
+    }
+
     @Override
     public ModelsMap postProcessModels(ModelsMap objs) {
         // process enum in models
@@ -1044,6 +1059,9 @@ public ModelsMap postProcessModels(ModelsMap objs) {
                     }
                 }
             }
+
+            // Sort model properties alphabetically to ensure deterministic code generation
+            sortModelPropertiesByName(cm);
         }
 
         return objs;