docs: add 0.48.1 changelog entry

Author: rudrankriyam

resources/changelog.mdx

@@ -14,6 +14,20 @@ The App Store Connect CLI follows semantic versioning. All releases are availabl
 
 No unreleased changes yet.
 
+### 0.48.1
+
+**Highlights**:
+
+* Product page optimization treatment localizations now support screenshot-set upload and sync commands
+* Windows private key permission checks are fixed for more reliable auth/setup workflows
+* Release guardrails are more stable after tightening a flaky mutating-request timeout test
+
+**Changes**:
+
+* `feat(product-pages)`: Add product page optimization treatment localization screenshot-set upload and sync commands
+* `fix(windows)`: Correct private key permission checks on Windows
+* `test(release)`: Stabilize the mutating request timeout refresh assertion used by release CI
+
 ### 0.48.0
 
 **Highlights**: