Fix ascii-frame-outer blink caused by JS/CSS hover conflict

JS mouseenter/mouseleave handlers were setting row.style.backgroundColor
inline, fighting with the CSS tr:hover rule. On mouseleave both fired
simultaneously causing a double repaint / blink. Removed the redundant
JS handlers — the CSS tr:hover transition already handles this cleanly.

Also removed body flicker animation from base.css (was still present
after being removed from dashboard.css).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

assets/css/base.css

@@ -166,8 +166,6 @@ body {
   line-height: 1.6;
   min-height: 100vh;
   overflow-x: hidden;
-  /* Subtle screen flicker every 30 s — authentic CRT feel */
-  animation: flicker 0.2s ease-in-out 30s infinite;
 }
 
 a {