docs(changelog): title 1.22.1 after its OpenCode Go highlight

The grouped notes put the OpenCode Go header change under Improvements, so
the site's headline fallback (first bold bullet) picked Message queue. The
explicit title keeps the release's most important change on the index.

Claude-Session: https://claude.ai/code/session_01VqV56Hez25hTxXH4ipJfzH

changelog/1.22.1.md

@@ -1,6 +1,7 @@
 ---
 version: 1.22.1
 date: 2026-09-04
+title: OpenCode Go header and a server-side message queue
 ---
 
 ## App

changelog/index.json

@@ -2,7 +2,7 @@
   {
     "version": "1.22.1",
     "date": "2026-09-04",
-    "title": null,
+    "title": "OpenCode Go header and a server-side message queue",
     "intro": null,
     "app": {
       "new": [