Restored original behavior in UrlUtils and relativeToTransformReady

- Use assignOptions instead of Object.assign in UrlUtils constructor to preserve undefined handling (filters out undefined values from user options, preserving defaults)
- Restore overrideOptions pattern in relativeToTransformReady to ensure secure: false is always forced regardless of user input
- Add trailing slash after replacement string in relativeToTransformReady to match original JavaScript behavior

Author: vershwal

packages/url-utils/src/UrlUtils.ts

@@ -108,7 +108,7 @@ export default class UrlUtils {
             staticMediaUrlPrefix: 'content/media'
         };
 
-        this._config = Object.assign({}, defaultOptions, options) as UrlUtilsConfig;
+        this._config = assignOptions({}, defaultOptions as unknown as Record<string, unknown>, options as unknown as Record<string, unknown>) as UrlUtilsConfig;
 
         const assetBaseUrls = options.assetBaseUrls || {};
         this._assetBaseUrls = {

packages/url-utils/src/utils/relative-to-transform-ready.ts

@@ -30,10 +30,12 @@ const relativeToTransformReady = function (
 
     const defaultOptions: RelativeToTransformReadyOptionsInput = {
         replacementStr: '__GHOST_URL__',
-        staticImageUrlPrefix: 'content/images',
+        staticImageUrlPrefix: 'content/images'
+    };
+    const overrideOptions: RelativeToTransformReadyOptionsInput = {
         secure: false
     };
-    const options = Object.assign({}, defaultOptions, finalOptions);
+    const options = Object.assign({}, defaultOptions, finalOptions, overrideOptions);
 
     // convert to absolute
     const absoluteUrl = relativeToAbsolute(url, root, finalItemPath, options);
@@ -53,7 +55,7 @@ const relativeToTransformReady = function (
 
         // replace root with replacement string
         const transformedUrl = absoluteUrl
-            .replace(normalizedRoot, `${options.replacementStr}`)
+            .replace(normalizedRoot, `${options.replacementStr}/`) // always have trailing slash after magic string
             .replace(/([^:])\/\//g, '$1/');
 
         return transformedUrl;