docs: weekly changelog update (#358)

Co-authored-by: yash-pouranik <172860064+yash-pouranik@users.noreply.github.com>

Author: yash-pouranik

mintlify/docs/changelog/july-2026.mdx

@@ -3,6 +3,12 @@ title: July 2026
 description: What's new in urBackend — new features, improvements, and fixes.
 ---
 
+<Update label="2026-07-20" description="Week of 2026-07-13–2026-07-20" tags={["Fix"]}>
+## Bug fixes
+
+- Fixed Social Auth Sign-Up Validation Failures ([#354](https://github.com/geturbackend/urBackend/pull/354) by [@AYUSH-P-SINGH](https://github.com/AYUSH-P-SINGH))
+</Update>
+
 <Update label="2026-07-13" description="Week of 2026-07-06–2026-07-13" tags={["Feature", "Improvement", "Fix"]}>
 ## New features