feat(typescript-axios,typescript-fetch): sort model properties alphabetically

Call sortModelPropertiesByName in postProcessModels to ensure
deterministic code generation and prevent unnecessary diffs
between generations.

Author: scarf005

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

@@ -291,6 +291,9 @@ public ModelsMap postProcessModels(ModelsMap objs) {
                     }
                 }
             }
+
+            // Sort model properties alphabetically to ensure deterministic code generation
+            sortModelPropertiesByName(cm);
         }
 
         // Apply the model file name to the imports as well

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

@@ -390,6 +390,9 @@ public ModelsMap postProcessModels(ModelsMap objs) {
             ExtendedCodegenModel cm = (ExtendedCodegenModel) mo.getModel();
             cm.imports = new TreeSet<>(cm.imports);
             this.processCodeGenModel(cm);
+
+            // Sort model properties alphabetically to ensure deterministic code generation
+            sortModelPropertiesByName(cm);
         }
 
         // Add supporting file only if we plan to generate files in /models