feat(web): split video and up rankings and add about page

reaction_board/web/static/style.css

@@ -891,3 +891,8 @@ h1, h2, h3, p { margin: 0; }
   .candidate-card { grid-template-columns: 84px minmax(0, 1fr); }
   .candidate-thumb { width: 84px; }
 }
+.about-page .panel + .panel { margin-top: 12px; }
+.about-page .panel h2 { font-size: 15px; margin-bottom: 8px; }
+.about-list { margin: 0; padding-left: 18px; display: grid; gap: 6px; font-size: 13px; line-height: 1.55; }
+.about-list code { padding: 1px 4px; border-radius: 4px; background: var(--accent-soft); font-size: 12px; }
+.about-list.about-weights { list-style: none; padding-left: 0; grid-template-columns: repeat(2, minmax(0, 1fr)); }