README: pull credentials line closer to slogan, drop <sub>

Same paragraph + <br/> between the two lines — visually grouped as
one tagline block.  Normal text size now reads as a real subtitle
rather than a footnote.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: WaylandYang

README.md

@@ -4,10 +4,8 @@
 
 <p align="center">
   <b><i>The first AI memory built to forget.</i></b>
-</p>
-
-<p align="center">
-  <sub>local-first &nbsp;·&nbsp; <b>97.4% R@5</b> on LongMemEval raw &nbsp;·&nbsp; zero API calls</sub>
+  <br />
+  local-first &nbsp;·&nbsp; <b>97.4% R@5</b> on LongMemEval raw &nbsp;·&nbsp; zero API calls
 </p>
 
 <p align="center">